Gurobi 5.0.1 (linux64) logging started Wed Apr 24 01:22:32 2013

Optimize a model with 31976 rows, 31416 columns and 125496 nonzeros
Presolve removed 2409 rows and 0 columns
Presolve time: 0.19s
Presolved: 29567 rows, 31416 columns, 120678 nonzeros
Variable types: 31360 continuous, 56 integer (56 binary)

Root relaxation: objective 5.683054e+04, 6551 iterations, 0.90 seconds

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

     0     0 56830.5390    0    4          - 56830.5390     -      -    1s
H    0     0                    57210.000000 56830.5390  0.66%     -    1s
H    0     0                    56865.000000 56830.5390  0.06%     -    1s
     0     0 56831.0813    0    5 56865.0000 56831.0813  0.06%     -    1s
     0     0 56831.0813    0    4 56865.0000 56831.0813  0.06%     -    2s
     0     0 56831.0987    0    5 56865.0000 56831.0987  0.06%     -    2s
     0     0 56831.3165    0    5 56865.0000 56831.3165  0.06%     -    2s
     0     0 56831.3165    0    5 56865.0000 56831.3165  0.06%     -    2s
     0     0 56863.5254    0    1 56865.0000 56863.5254  0.00%     -    2s

Cutting planes:
  Gomory: 1
  Flow cover: 2

Explored 0 nodes (8588 simplex iterations) in 2.43 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 5.686500000000e+04, best bound 5.686352542373e+04, gap 0.0026%