Gurobi 5.0.1 (linux64) logging started Wed Apr 24 01:33:45 2013

Optimize a model with 36660 rows, 36060 columns and 144060 nonzeros
Presolve removed 2295 rows and 0 columns
Presolve time: 0.21s
Presolved: 34365 rows, 36060 columns, 139470 nonzeros
Variable types: 36000 continuous, 60 integer (60 binary)

Root relaxation: objective 6.796511e+04, 7327 iterations, 1.03 seconds

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

     0     0 67965.1106    0    3          - 67965.1106     -      -    1s
H    0     0                    69092.000000 67965.1106  1.63%     -    1s
H    0     0                    68130.000000 67965.1106  0.24%     -    1s
     0     0 67967.9018    0    5 68130.0000 67967.9018  0.24%     -    1s
     0     0 67969.0543    0    5 68130.0000 67969.0543  0.24%     -    1s
     0     0 67969.0543    0    5 68130.0000 67969.0543  0.24%     -    2s
     0     0 67969.0543    0    3 68130.0000 67969.0543  0.24%     -    3s
     0     0 67969.4800    0    5 68130.0000 67969.4800  0.24%     -    4s
     0     2 67979.4305    0    5 68130.0000 67979.4305  0.22%     -    4s
*    6     3               5    68107.000000 67979.4305  0.19%  38.2    4s
*    9     0               3    68097.000000 68097.0000   0.0%  50.4    4s

Cutting planes:
  Gomory: 2
  Flow cover: 3

Explored 10 nodes (10837 simplex iterations) in 4.93 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 6.809700000000e+04, best bound 6.809700000000e+04, gap 0.0%