Gurobi 5.0.1 (linux64) logging started Tue Nov 20 05:48:40 2012

Optimize a model with 173 rows, 57 columns and 346 nonzeros
Presolve removed 53 rows and 2 columns
Presolve time: 0.00s
Presolved: 120 rows, 55 columns, 276 nonzeros
Variable types: 0 continuous, 55 integer (55 binary)
Found heuristic solution: objective 18.0000000

Root relaxation: objective 2.300000e+01, 74 iterations, 0.00 seconds

    Nodes    |    Current Node    |     Objective Bounds      |     Work
 Expl Unexpl |  Obj  Depth IntInf | Incumbent    BestBd   Gap | It/Node Time

     0     0   23.00000    0   46   18.00000   23.00000  27.8%     -    0s
H    0     0                      19.0000000   23.00000  21.1%     -    0s
     0     0   23.00000    0   42   19.00000   23.00000  21.1%     -    0s
H    0     0                      20.0000000   23.00000  15.0%     -    0s
H    0     0                      21.0000000   23.00000  9.52%     -    0s
     0     0   23.00000    0   40   21.00000   23.00000  9.52%     -    0s
     0     0   22.75000    0   47   21.00000   22.75000  8.33%     -    0s
     0     0   22.42857    0   51   21.00000   22.42857  6.80%     -    0s
     0     0   22.27273    0   51   21.00000   22.27273  6.06%     -    0s
     0     0   22.11111    0   52   21.00000   22.11111  5.29%     -    0s
     0     0   22.00000    0   52   21.00000   22.00000  4.76%     -    0s
     0     0   22.00000    0   49   21.00000   22.00000  4.76%     -    0s
     0     0     cutoff    0        21.00000   21.99998  4.76%     -    0s

Cutting planes:
  Gomory: 1
  Zero half: 20

Explored 0 nodes (260 simplex iterations) in 0.02 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 2.100000000000e+01, best bound 2.100000000000e+01, gap 0.0%