Trace number 2690577

Some explanations

A solver is run under the control of another program named runsolver. runsolver is in charge of imposing the CPU time limit and the memory limit to the solver. It also monitors some information about the process. The trace of the execution of a solver is divided into four (or five) parts:
  1. SOLVER DATA
    This is the output of the solver (stdout and stderr).
    Note that some very long lines in this section may be truncated by your web browser ! In such a case, you may want to use the "Download as text" link to get the trace as a text file.

    When the --timestamp option is passed to the runsolver program, each line output by the solver is prepended with a timestamp which indicates at what time the line was output by the solver. Times are relative to the start of the program, given in seconds. The first timestamp (if present) is estimated CPU time. The last timestamp is wall clock time.

    As some 'v lines' may be very long (sometimes several megabytes), the 'v line' output by your solver may be split on several lines to help limit the size of the trace recorded in the database. In any case, the exact output of your solver is preserved in a trace file.
  2. VERIFIER DATA
    The output of the solver is piped to a verifier program which will search a value line "v " and, if found, will check that the given interpretation satisfies all constraints.
  3. CONVERSION SCRIPT DATA (Optionnal)
    When a conversion script is used, this section shows the messages that were output by the conversion script.
  4. WATCHER DATA
    This is the informations gathered by the runsolver program. It first prints the different limits. There's a first limit on CPU time set to X seconds (see the parameters in the trace). After this time has ellapsed, runsolver sends a SIGTERM and 2 seconds later a SIGKILL to the solver. For safety, there's also another limit set to X+30 seconds which will send a SIGXPU to the solver. The last limit is on the virtual memory used by the process (see the parameters in the trace).
    Every ten seconds, the runsolver process fetches the content of /proc/loadavg, /proc/pid/stat and /proc/pid/statm (see man proc) and prints it as raw data. This is only recorded in case we need to investigate the behaviour of a solver. The memory used by the solver (vsize) is also given every ten seconds.
    When the solver exits, runsolver prints some informations such as status and time. CPU usage is the ratio CPU Time/Real Time.
  5. LAUNCHER DATA
    These informations are related to the script which will launch the solver. The most important informations are the command line given to the solver, the md5sum of the different files and the dump of the /proc/cpuinfo and /proc/meminfo which provides some useful information on the computer.

Solver answer on this benchmark

Solver NameAnswerCPU timeWall clock time
wbo 1.4bWrong UNSAT 4.15137 4.15494

General information on the benchmark

Name/PARTIAL-SMALLINT-LIN/PB06/submitted-PB06/namasivayam/wnqueen/
normalized-t2001.13queen13.1110971363--soft-33-100-0.wbo
MD5SUM9aae741b51a1836a01c8daeb1bffcdf7
Bench CategoryPARTIAL-SMALLINT-LIN (both soft and hard constraints, small integers, linear constraints)
Best result obtained on this benchmarkMOPT
Best cost obtained on this benchmark25
Best CPU time to get the best result obtained on this benchmark0.331948
Max-Satisfiable
Max-(Un)Satisfiability was proved
Best value of the cost
Optimality of the best cost was proved
Number of variables169
Total number of constraints101
Number of soft constraints69
Number of constraints which are clauses30
Number of constraints which are cardinality constraints (but not clauses)70
Number of constraints which are nor clauses,nor cardinality constraints1
Minimum length of a constraint2
Maximum length of a constraint169
Top cost 3204
Min constraint cost 1
Max constraint cost 97
Sum of constraints costs 3203
Biggest number in a constraint 38
Number of bits of the biggest number in a constraint 6
Biggest sum of numbers in a constraint 1228
Number of bits of the biggest sum of numbers11
Number of products (including duplicates)0
Sum of products size (including duplicates)0
Number of different products0
Sum of products size0

Solver Data 

0.00/0.00	c wbo 1.4 beta - 20100610
0.00/0.00	c Parsing wbo file format. File HOME/instance-2690577-1277898923.wbo.
0.00/0.00	c Instance file HOME/instance-2690577-1277898923.wbo
0.00/0.00	c File size is 10301 bytes.
0.00/0.00	c Highest Coefficient sum: 1228
0.00/0.00	c ============================[ Problem Statistics ]=============================
0.00/0.00	c |                                                                             |
0.00/0.00	c |  Parsing time:          0.00         s                                      |
0.00/0.00	c |  Number Variables:      169                                                 |
0.00/0.00	c |  Number Clauses:        30                                                  |
0.00/0.00	c |  Number Cardinality:    70                                                  |
0.00/0.00	c |  Number PB Constraints: 1                                                   |
0.00/0.00	c ============================[ Search Statistics ]==============================
0.00/0.00	c | Conflicts |          ORIGINAL         |          LEARNT          | Progress |
0.00/0.00	c |           |    Vars     Ctrs     Lits |    Limit  Clauses Lit/Cl |          |
0.00/0.00	c ===============================================================================
0.00/0.00	c |         0 |     169      101     1205 |     5000        0    nan |  0.000 % |
0.00/0.00	c |       101 |     169      101     1205 |     5500      101     46 |  0.004 % |
0.00/0.00	c |       251 |     169      101     1205 |     6050      251     37 |  0.004 % |
0.00/0.01	c |       479 |     169      101     1205 |     6655      479     35 |  0.004 % |
0.02/0.02	c |       820 |     169      101     1205 |     7320      820     35 |  0.004 % |
0.02/0.03	c |      1327 |     169      101     1205 |     8052     1327     36 |  0.004 % |
0.02/0.06	c |      2088 |     169      101     1205 |     8857     2088     37 |  0.004 % |
0.09/0.10	c |      3227 |     169      101     1205 |     9743     3227     35 |  0.004 % |
0.09/0.17	c |      4935 |     169      101     1205 |    10717     4935     36 |  0.004 % |
0.29/0.30	c |      7497 |     169      101     1205 |    11789     7497     38 |  0.004 % |
0.48/0.52	c |     11345 |     169      101     1205 |    12968    11345     41 |  0.004 % |
0.88/0.90	c |     17111 |     169      101     1205 |    14265    10565     45 |  0.004 % |
1.49/1.51	c |     25760 |     169      101     1205 |    15692    12027     46 |  0.004 % |
2.58/2.64	c |     38734 |     169      101     1205 |    17261     9212     48 |  0.004 % |
4.09/4.13	c |     58196 |     124      101     1205 |    18987     2517     44 | 26.816 % |
4.09/4.15	s UNSATISFIABLE
4.09/4.15	c Total CPU time: 4.01539 s
4.09/4.15	c ===============================================================================
4.09/4.15	c 
4.09/4.15	s UNSATISFIABLE

Verifier Data 

ERROR: no interpretation found !

Watcher Data 

runsolver version 3.2.9 (svn:492) (c) roussel@cril.univ-artois.fr

command line: BIN/runsolver --timestamp -w /tmp/evaluation-result-2690577-1277898923/watcher-2690577-1277898923 -o /tmp/evaluation-result-2690577-1277898923/solver-2690577-1277898923 -C 1800 -W 2000 -M 3800 wbo1.4b -file-format=wbo -time-limit=1800 HOME/instance-2690577-1277898923.wbo 

Enforcing CPUTime limit (soft limit, will send SIGTERM then SIGKILL): 1800 seconds
Enforcing CPUTime limit (hard limit, will send SIGXCPU): 1830 seconds
Enforcing wall clock limit (soft limit, will send SIGTERM then SIGKILL): 2000 seconds
Enforcing VSIZE limit (soft limit, will send SIGTERM then SIGKILL): 3891200 KiB
Enforcing VSIZE limit (hard limit, stack expansion will fail with SIGSEGV, brk() and mmap() will return ENOMEM): 3942400 KiB
Current StackSize limit: 10240 KiB


[startup+0 s]
/proc/loadavg: 2.00 2.02 2.00 4/178 23000
/proc/meminfo: memFree=30072224/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=2568 CPUtime=0
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 289 0 0 0 0 0 0 0 20 0 1 0 163531874 2629632 205 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 2 0 0 0
/proc/23000/statm: 642 205 144 303 0 337 0

[startup+0.0214309 s]
/proc/loadavg: 2.00 2.02 2.00 4/178 23000
/proc/meminfo: memFree=30072224/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=2700 CPUtime=0.02
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 334 0 0 0 2 0 0 0 20 0 1 0 163531874 2764800 250 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 2 0 0 0
/proc/23000/statm: 675 250 144 303 0 370 0
Current children cumulated CPU time (s) 0.02
Current children cumulated vsize (KiB) 2700

[startup+0.100409 s]
/proc/loadavg: 2.00 2.02 2.00 4/178 23000
/proc/meminfo: memFree=30072224/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=3492 CPUtime=0.09
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 518 0 0 0 9 0 0 0 20 0 1 0 163531874 3575808 434 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 7 0 0 0
/proc/23000/statm: 873 434 144 303 0 568 0
Current children cumulated CPU time (s) 0.09
Current children cumulated vsize (KiB) 3492

[startup+0.300342 s]
/proc/loadavg: 2.00 2.02 2.00 4/178 23000
/proc/meminfo: memFree=30072224/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=4948 CPUtime=0.29
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 872 0 0 0 28 1 0 0 20 0 1 0 163531874 5066752 788 4089446400 134512640 135752675 4289839712 18446744073709551615 134605412 0 0 4096 3 0 0 0 17 5 0 0 0
/proc/23000/statm: 1237 788 144 303 0 932 0
Current children cumulated CPU time (s) 0.29
Current children cumulated vsize (KiB) 4948

[startup+0.700273 s]
/proc/loadavg: 2.00 2.02 2.00 4/178 23000
/proc/meminfo: memFree=30072224/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=7060 CPUtime=0.68
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 1411 0 0 0 66 2 0 0 21 0 1 0 163531874 7229440 1327 4089446400 134512640 135752675 4289839712 18446744073709551615 134611778 0 0 4096 3 0 0 0 17 5 0 0 0
/proc/23000/statm: 1765 1327 144 303 0 1460 0
Current children cumulated CPU time (s) 0.68
Current children cumulated vsize (KiB) 7060

[startup+1.50018 s]
/proc/loadavg: 2.00 2.02 2.00 3/179 23001
/proc/meminfo: memFree=30064652/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=11152 CPUtime=1.49
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 2439 0 0 0 144 5 0 0 23 0 1 0 163531874 11419648 2355 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 3 0 0 0
/proc/23000/statm: 2788 2355 144 303 0 2483 0
Current children cumulated CPU time (s) 1.49
Current children cumulated vsize (KiB) 11152

[startup+3.10091 s]
/proc/loadavg: 2.00 2.02 2.00 3/179 23001
/proc/meminfo: memFree=30058372/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=17752 CPUtime=3.09
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 4089 0 0 0 299 10 0 0 25 0 1 0 163531874 18178048 4005 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 3 0 0 0
/proc/23000/statm: 4438 4005 144 303 0 4133 0
Current children cumulated CPU time (s) 3.09
Current children cumulated vsize (KiB) 17752

Solver just ended. Dumping a history of the last processes samples

[startup+3.90078 s]
/proc/loadavg: 2.00 2.02 2.00 3/179 23001
/proc/meminfo: memFree=30052544/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=21448 CPUtime=3.89
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 4998 0 0 0 377 12 0 0 25 0 1 0 163531874 21962752 4914 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 3 0 0 0
/proc/23000/statm: 5362 4914 144 303 0 5057 0
Current children cumulated CPU time (s) 3.89
Current children cumulated vsize (KiB) 21448

[startup+4.10074 s]
/proc/loadavg: 2.00 2.02 2.00 3/179 23001
/proc/meminfo: memFree=30052544/32951124 swapFree=67111528/67111528
[pid=23000] ppid=22998 vsize=22372 CPUtime=4.09
/proc/23000/stat : 23000 (wbo1.4b) R 22998 23000 20735 0 -1 4202496 5253 0 0 0 396 13 0 0 25 0 1 0 163531874 22908928 5169 4089446400 134512640 135752675 4289839712 18446744073709551615 135271249 0 0 4096 3 0 0 0 17 3 0 0 0
/proc/23000/statm: 5593 5169 144 303 0 5288 0
Current children cumulated CPU time (s) 4.09
Current children cumulated vsize (KiB) 22372

Child status: 0
Real time (s): 4.15494
CPU time (s): 4.15137
CPU user time (s): 4.01539
CPU system time (s): 0.135979
CPU usage (%): 99.914
Max. virtual memory (cumulated for all children) (KiB): 22372

getrusage(RUSAGE_CHILDREN,...) data:
user time used= 4.01539
system time used= 0.135979
maximum resident set size= 0
integral shared memory size= 0
integral unshared data size= 0
integral unshared stack size= 0
page reclaims= 5350
page faults= 0
swaps= 0
block input operations= 0
block output operations= 0
messages sent= 0
messages received= 0
signals received= 0
voluntary context switches= 1
involuntary context switches= 66

runsolver used 0.003999 second user time and 0.017997 second system time

The end

Launcher Data 

Begin job on node118 at 2010-06-30 13:55:23
IDJOB=2690577
IDBENCH=78850
IDSOLVER=1201
FILE ID=node118/2690577-1277898923
PBS_JOBID= 11197117
Free space on /tmp= 74208 MiB

SOLVER NAME= wbo 1.4b
BENCH NAME= PB10/normalized-PB10/PARTIAL-SMALLINT-LIN/PB06/submitted-PB06/namasivayam/wnqueen/normalized-t2001.13queen13.1110971363--soft-33-100-0.wbo
COMMAND LINE= wbo1.4b -file-format=wbo -time-limit=TIMEOUT BENCHNAME
RUNSOLVER COMMAND LINE= BIN/runsolver --timestamp -w /tmp/evaluation-result-2690577-1277898923/watcher-2690577-1277898923 -o /tmp/evaluation-result-2690577-1277898923/solver-2690577-1277898923 -C 1800 -W 2000 -M 3800  wbo1.4b -file-format=wbo -time-limit=1800 HOME/instance-2690577-1277898923.wbo

TIME LIMIT= 1800 seconds
MEMORY LIMIT= 3800 MiB
MAX NB THREAD= 0

MD5SUM BENCH= 9aae741b51a1836a01c8daeb1bffcdf7
RANDOM SEED=791989460

node118.alineos.net Linux 2.6.18-164.el5 #1 SMP Thu Sep 3 03:28:30 EDT 2009

/proc/cpuinfo:
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 4
apicid		: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5333.58
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 0
cpu cores	: 4
apicid		: 16
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5332.75
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 2
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 1
cpu cores	: 4
apicid		: 2
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5332.76
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 1
cpu cores	: 4
apicid		: 18
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5332.83
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 4
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 2
cpu cores	: 4
apicid		: 4
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5332.75
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 5
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 2
cpu cores	: 4
apicid		: 20
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5332.83
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 6
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 6
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5332.75
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]

processor	: 7
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
cpu MHz		: 2666.791
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 22
fpu		: yes
fpu_exception	: yes
cpuid level	: 11
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx rdtscp lm constant_tsc ida nonstop_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr popcnt lahf_lm
bogomips	: 5448.09
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management: [8]


/proc/meminfo:
MemTotal:     32951124 kB
MemFree:      30072256 kB
Buffers:        181620 kB
Cached:        1297672 kB
SwapCached:          0 kB
Active:        1725220 kB
Inactive:      1008756 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:     32951124 kB
LowFree:      30072256 kB
SwapTotal:    67111528 kB
SwapFree:     67111528 kB
Dirty:            2736 kB
Writeback:           0 kB
AnonPages:     1254596 kB
Mapped:          15336 kB
Slab:            78020 kB
PageTables:       7440 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
CommitLimit:  83587088 kB
Committed_AS:  1398440 kB
VmallocTotal: 34359738367 kB
VmallocUsed:    296008 kB
VmallocChunk: 34359440975 kB
HugePages_Total:     0
HugePages_Free:      0
HugePages_Rsvd:      0
Hugepagesize:     2048 kB

Free space on /tmp at the end= 74208 MiB
End job on node118 at 2010-06-30 13:55:27