Gurobi 5.0.1 (linux64) logging started Wed Apr 24 02:02:13 2013

Optimize a model with 45627 rows, 44957 columns and 179627 nonzeros
Presolve removed 3870 rows and 0 columns
Presolve time: 0.27s
Presolved: 41757 rows, 44957 columns, 171887 nonzeros
Variable types: 44890 continuous, 67 integer (67 binary)

Root relaxation: objective 6.855040e+04, 7786 iterations, 1.28 seconds

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

     0     0 68550.3986    0    6          - 68550.3986     -      -    1s
H    0     0                    70522.000000 68550.3986  2.80%     -    1s
     0     0 68551.2141    0    5 70522.0000 68551.2141  2.79%     -    2s
H    0     0                    70177.000000 68551.2141  2.32%     -    2s
     0     0 68551.2168    0    5 70177.0000 68551.2168  2.32%     -    2s
     0     2 68570.0294    0    5 70177.0000 68570.0294  2.29%     -    3s
H    4     4                    70095.727382 68631.5168  2.09%   176    4s
     7     9 68962.1219    5    2 70095.7274 68631.5168  2.09%   298    5s
H    9     8                    68839.185185 68631.5168  0.30%   238    5s
H   10     6                    68835.622642 68631.5168  0.30%   220    5s
H   12     7                    68830.473684 68631.5168  0.29%   193    5s
*   13     7              11    68816.000000 68631.5168  0.27%   180    5s
H   27     1                    68784.000000 68708.9235  0.11%   156    6s
*   37     2               6    68769.000000 68752.9878  0.02%   135    6s

Cutting planes:
  Gomory: 1
  Flow cover: 5

Explored 40 nodes (12929 simplex iterations) in 6.56 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 6.876900000000e+04, best bound 6.876900000000e+04, gap 0.0%