Gurobi 5.0.1 (linux64) logging started Mon Feb  4 18:54:34 2013

Optimize a model with 19649 rows, 2401 columns and 60025 nonzeros
Presolve removed 3673 rows and 1264 columns
Presolve time: 0.14s
Presolved: 15976 rows, 1137 columns, 48799 nonzeros
Variable types: 19 continuous, 1118 integer (1118 binary)
Found heuristic solution: objective 39439.000000

Root relaxation: objective 3.187627e+04, 4081 iterations, 0.22 seconds

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

     0     0 31876.2667    0    8 39439.0000 31876.2667  19.2%     -    0s
H    0     0                    31887.000000 31876.2667  0.03%     -    0s
H    0     0                    31885.000000 31876.2667  0.03%     -    0s
     0     0 31877.0000    0   13 31885.0000 31877.0000  0.03%     -    0s
     0     0 31877.0000    0   11 31885.0000 31877.0000  0.03%     -    0s
     0     0 31877.0000    0   14 31885.0000 31877.0000  0.03%     -    0s
     0     0 31877.0000    0   16 31885.0000 31877.0000  0.03%     -    0s
     0     0 31877.0000    0   22 31885.0000 31877.0000  0.03%     -    0s
H    0     0                    31884.000000 31877.0000  0.02%     -    0s
     0     0 31877.0000    0   23 31884.0000 31877.0000  0.02%     -    0s
     0     0 31877.0000    0   22 31884.0000 31877.0000  0.02%     -    0s
H    0     0                    31883.000000 31877.0000  0.02%     -    0s
     0     2 31877.0000    0   18 31883.0000 31877.0000  0.02%     -    0s
*   29    18              21    31881.000000 31877.3973  0.01%  13.5    0s

Cutting planes:
  Gomory: 1
  MIR: 19
  Zero half: 1
  Mod-K: 2

Explored 51 nodes (5399 simplex iterations) in 0.69 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 3.188100000000e+04, best bound 3.187900000000e+04, gap 0.0063%