Trace number 4263934

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 NameAnswerobjective functionCPU timeWall clock time
AbsCon-basic 2017-06-11OPT4 1.1658601 0.77239501

DiagnosticValue
WRONG_DECISIONS72

General information on the benchmark

NameGraphColoring/GraphColoring-m1-mono/
GraphColoring-2-fullins-3.xml
MD5SUM73fd83f8962f0084b0563a84899fe1a3
Bench CategoryCOP (optimization problem)
Best result obtained on this benchmarkOPT
Best value of the objective obtained on this benchmark4
Best CPU time to get the best result obtained on this benchmark0.149295
Satisfiable
(Un)Satisfiability was proved
Number of variables52
Number of constraints201
Number of domains1
Minimum domain size52
Maximum domain size52
Distribution of domain sizes[{"size":52,"count":52}]
Minimum variable degree5
Maximum variable degree16
Distribution of variable degrees[{"degree":5,"count":4},{"degree":6,"count":10},{"degree":7,"count":6},{"degree":8,"count":16},{"degree":11,"count":4},{"degree":12,"count":8},{"degree":16,"count":4}]
Minimum constraint arity2
Maximum constraint arity2
Distribution of constraint arities[{"arity":2,"count":201}]
Number of extensional constraints0
Number of intensional constraints201
Distribution of constraint types[{"type":"intension","count":201}]
Optimization problemYES
Type of objectivemin MAXIMUM

Solver Data 

0.38/0.40	
0.38/0.40	AbsCon 2 
0.38/0.40	
0.72/0.62	  Solving XCSP3-instance-4263934-1502272942 as a COP in -infty..+infty
0.72/0.62	  Loading variables...
0.72/0.65	  Loading constraints...
0.96/0.71	  Solver SolverBacktrack being built...
0.96/0.71	
0.96/0.74	  Preprocessing : gac=true, ccks=0, filters=0, revisions=0 (useless=0), AC=0, removals=0, inconsistent=false
0.96/0.74	
0.96/0.75	o 4
0.96/0.76	
0.96/0.76	v <instantiation id='sol1' type='solution' cost='4'>  <list> x[] </list>  <values> 0 2 1 1 2 2 3 3 1 2 3 4 3 2 3 3 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 0 1 2 3 </values>  </instantiation>
0.96/0.76	s OPTIMUM FOUND
0.96/0.76	
0.96/0.76	d WRONG_DECISIONS 72

Verifier Data 

OK	4

Watcher Data 

runsolver Copyright (C) 2010-2013 Olivier ROUSSEL

This is runsolver version 3.3.7 (svn: 2553)

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

command line: BIN/runsolver --timestamp -w /tmp/evaluation-result-4263934-1502272942/watcher-4263934-1502272942 -o /tmp/evaluation-result-4263934-1502272942/solver-4263934-1502272942 -C 2520 -W 2520 -M 15500 --bin-var /tmp/runsolver-exch-node135-1502259017-17571 --watchdog 2580 java -jar HOME/AbsCon-basic.jar HOME/instance-4263934-1502272942.xml 

pid=19626
running on 4 cores: 1,3,5,7

Enforcing CPUTime limit (soft limit, will send SIGTERM then SIGKILL): 2520 seconds
Enforcing CPUTime limit (hard limit, will send SIGXCPU): 2550 seconds
Enforcing wall clock limit (soft limit, will send SIGTERM then SIGKILL): 2520 seconds
Enforcing VSIZE limit (soft limit, will send SIGTERM then SIGKILL): 15872000 KiB
Enforcing VSIZE limit (hard limit, stack expansion will fail with SIGSEGV, brk() and mmap() will return ENOMEM): 15923200 KiB
Current StackSize limit: 8192 KiB


[startup+0 s]
/proc/loadavg: 2.00 1.92 1.75 3/200 19629
/proc/meminfo: memFree=30857000/32770624 swapFree=0/401056
[pid=19629] ppid=19626 vsize=23672 CPUtime=0 cores=1,3,5,7
/proc/19629/stat : 19629 (runsolver) D 19626 19629 9153 0 -1 4202560 108 0 0 0 0 0 0 0 20 0 1 0 69205303 24240128 106 18446744073709551615 4194304 4338465 140721346612160 140721346609800 139964466016983 0 0 1 24578 18446744071580418449 0 0 17 3 0 0 0 0 0 6438912 6441760 10797056 140721346613407 140721346613833 140721346613833 140721346617290 0
/proc/19629/statm: 5918 106 53 36 0 2156 0

[startup+0.100141 s]
/proc/loadavg: 2.00 1.92 1.75 3/200 19629
/proc/meminfo: memFree=30857000/32770624 swapFree=0/401056
[pid=19629] ppid=19626 vsize=98704 CPUtime=0 cores=1,3,5,7
/proc/19629/stat : 19629 (java) S 19626 19629 9153 0 -1 1077944320 1369 0 0 0 0 0 0 0 20 0 2 0 69205303 101072896 1168 18446744073709551615 4194304 4196468 140735060265392 140735060247936 140668974227191 0 0 1 0 18446744073709551615 0 0 17 7 0 0 9 0 0 6293624 6294260 26255360 140735060267469 140735060267598 140735060267598 140735060271055 0
/proc/19629/statm: 24932 1168 869 1 0 17056 0
Current children cumulated CPU time (s) 0
Current children cumulated vsize (KiB) 98704

[startup+0.200313 s]
/proc/loadavg: 2.00 1.92 1.75 3/200 19629
/proc/meminfo: memFree=30857000/32770624 swapFree=0/401056
[pid=19629] ppid=19626 vsize=10484492 CPUtime=0.06 cores=1,3,5,7
/proc/19629/stat : 19629 (java) S 19626 19629 9153 0 -1 1077944320 4799 0 0 0 5 1 0 0 20 0 14 0 69205303 10736119808 5842 18446744073709551615 4194304 4196468 140735060265392 140735060247936 140668974227191 0 0 1 16800974 18446744073709551615 0 0 17 7 0 0 9 0 0 6293624 6294260 26255360 140735060267469 140735060267598 140735060267598 140735060271055 0
/proc/19629/statm: 2621123 5842 2579 1 0 2610620 0
Current children cumulated CPU time (s) 0.06
Current children cumulated vsize (KiB) 10484492

[startup+0.303975 s]
/proc/loadavg: 2.00 1.92 1.75 3/200 19629
/proc/meminfo: memFree=30857000/32770624 swapFree=0/401056
[pid=19629] ppid=19626 vsize=10551180 CPUtime=0.19 cores=1,3,5,7
/proc/19629/stat : 19629 (java) S 19626 19629 9153 0 -1 1077944320 6072 0 0 0 18 1 0 0 20 0 15 0 69205303 10804408320 7514 18446744073709551615 4194304 4196468 140735060265392 140735060247936 140668974227191 0 0 1 16800974 18446744073709551615 0 0 17 7 0 0 9 0 0 6293624 6294260 26255360 140735060267469 140735060267598 140735060267598 140735060271055 0
/proc/19629/statm: 2637795 7514 2869 1 0 2627261 0
Current children cumulated CPU time (s) 0.19
Current children cumulated vsize (KiB) 10551180

[startup+0.70033 s]
/proc/loadavg: 2.00 1.92 1.75 3/200 19629
/proc/meminfo: memFree=30857000/32770624 swapFree=0/401056
[pid=19629] ppid=19626 vsize=10621952 CPUtime=0.96 cores=1,3,5,7
/proc/19629/stat : 19629 (java) S 19626 19629 9153 0 -1 1077944320 12655 0 0 0 90 6 0 0 20 0 16 0 69205303 10876878848 17891 18446744073709551615 4194304 4196468 140735060265392 140735060247936 140668974227191 0 0 1 16800974 18446744073709551615 0 0 17 7 0 0 9 0 0 6293624 6294260 26255360 140735060267469 140735060267598 140735060267598 140735060271055 0
/proc/19629/statm: 2655488 17891 3053 1 0 2644414 0
Current children cumulated CPU time (s) 0.96
Current children cumulated vsize (KiB) 10621952

Solver just ended.
??? exit watcher main loop
??? sigkill at end of watcher main loop
??? kill 19629 sig 9
??? end of watcher thread
Dumping a history of the last processes samples

[startup+0.70033 s]
/proc/loadavg: 2.00 1.92 1.75 3/200 19629
/proc/meminfo: memFree=30857000/32770624 swapFree=0/401056
[pid=19629] ppid=19626 vsize=10621952 CPUtime=0.96 cores=1,3,5,7
/proc/19629/stat : 19629 (java) S 19626 19629 9153 0 -1 1077944320 12655 0 0 0 90 6 0 0 20 0 16 0 69205303 10876878848 17891 18446744073709551615 4194304 4196468 140735060265392 140735060247936 140668974227191 0 0 1 16800974 18446744073709551615 0 0 17 7 0 0 9 0 0 6293624 6294260 26255360 140735060267469 140735060267598 140735060267598 140735060271055 0
/proc/19629/statm: 2655488 17891 3053 1 0 2644414 0
Current children cumulated CPU time (s) 0.96
Current children cumulated vsize (KiB) 10621952

Child status: 0
Real time (s): 0.772395
CPU time (s): 1.16586
CPU user time (s): 1.0982
CPU system time (s): 0.067661
CPU usage (%): 150.941
Max. virtual memory (cumulated for all children) (KiB): 10621952

getrusage(RUSAGE_CHILDREN,...) data:
user time used= 1.0982
system time used= 0.067661
maximum resident set size= 86988
integral shared memory size= 0
integral unshared data size= 0
integral unshared stack size= 0
page reclaims= 13376
page faults= 0
swaps= 0
block input operations= 0
block output operations= 72
messages sent= 0
messages received= 0
signals received= 0
voluntary context switches= 1663
involuntary context switches= 3

??? join timestamper begins
??? join timestamper ends
??? end of timestamper thread
runsolver used 0.003266 second user time and 0.007198 second system time

The end

Launcher Data 

Begin job on node135 at 2017-08-09 11:48:26
IDJOB=4263934
IDBENCH=120642
IDSOLVER=2652
FILE ID=node135/4263934-1502272942
RUNJOBID= node135-1502259017-17571
PBS_JOBID= 
Free space on /tmp= 62020 MiB

SOLVER NAME= AbsCon-basic 2017-06-11
BENCH NAME= XCSP17/GraphColoring/GraphColoring-m1-mono/GraphColoring-2-fullins-3.xml
COMMAND LINE= java -jar HOME/AbsCon-basic.jar BENCHNAME
RUNSOLVER COMMAND LINE= BIN/runsolver --timestamp -w /tmp/evaluation-result-4263934-1502272942/watcher-4263934-1502272942 -o /tmp/evaluation-result-4263934-1502272942/solver-4263934-1502272942 -C 2520 -W 2520 -M 15500 --bin-var /tmp/runsolver-exch-node135-1502259017-17571 --watchdog 2580  java -jar HOME/AbsCon-basic.jar HOME/instance-4263934-1502272942.xml

TIME LIMIT= 2520 seconds
MEMORY LIMIT= 15500 MiB
NBCORE= 4

MD5SUM BENCH= 73fd83f8962f0084b0563a84899fe1a3
RANDOM SEED=698952821

node135.alineos.net Linux 3.10.0-514.16.1.el7.x86_64 #1 SMP Wed Apr 12 15:04:24 UTC 2017

/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor:
performance

/proc/cpuinfo:
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 0
cpu cores	: 4
apicid		: 0
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5333.21
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 0
cpu cores	: 4
apicid		: 16
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5332.55
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 2
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 1
cpu cores	: 4
apicid		: 2
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5333.21
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 3
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 1
cpu cores	: 4
apicid		: 18
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5332.55
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 4
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 2
cpu cores	: 4
apicid		: 4
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5333.21
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 5
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 2
cpu cores	: 4
apicid		: 20
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5332.55
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 6
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 0
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 6
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5333.21
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:

processor	: 7
vendor_id	: GenuineIntel
cpu family	: 6
model		: 26
model name	: Intel(R) Xeon(R) CPU           X5550  @ 2.67GHz
stepping	: 5
microcode	: 0x19
cpu MHz		: 2668.000
cache size	: 8192 KB
physical id	: 1
siblings	: 4
core id		: 3
cpu cores	: 4
apicid		: 22
initial 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 pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt lahf_lm ida dtherm tpr_shadow vnmi flexpriority ept vpid
bogomips	: 5332.55
clflush size	: 64
cache_alignment	: 64
address sizes	: 40 bits physical, 48 bits virtual
power management:


/proc/meminfo:
MemTotal:       32770624 kB
MemFree:        30856740 kB
MemAvailable:   31526708 kB
Buffers:          258016 kB
Cached:           697068 kB
SwapCached:            0 kB
Active:          1052144 kB
Inactive:         426004 kB
Active(anon):     522992 kB
Inactive(anon):    24948 kB
Active(file):     529152 kB
Inactive(file):   401056 kB
Unevictable:           0 kB
Mlocked:               0 kB
SwapTotal:      67108860 kB
SwapFree:       67108860 kB
Dirty:              7656 kB
Writeback:             0 kB
AnonPages:        522952 kB
Mapped:            56624 kB
Shmem:             25272 kB
Slab:             138508 kB
SReclaimable:     111188 kB
SUnreclaim:        27320 kB
KernelStack:        3536 kB
PageTables:         5680 kB
NFS_Unstable:          0 kB
Bounce:                0 kB
WritebackTmp:          0 kB
CommitLimit:    83494172 kB
Committed_AS:    1540444 kB
VmallocTotal:   34359738367 kB
VmallocUsed:      354332 kB
VmallocChunk:   34341910524 kB
HardwareCorrupted:     0 kB
AnonHugePages:    415744 kB
HugePages_Total:       0
HugePages_Free:        0
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB
DirectMap4k:      122240 kB
DirectMap2M:    33423360 kB

Free space on /tmp at the end= 62012 MiB
End job on node135 at 2017-08-09 11:48:27