Gurobi 5.0.1 (linux64) logging started Sat Dec  8 03:30:40 2012

Optimize a model with 555 rows, 540 columns and 1772 nonzeros
Presolve removed 53 rows and 30 columns
Presolve time: 0.01s
Presolved: 502 rows, 510 columns, 1652 nonzeros
Variable types: 337 continuous, 173 integer (173 binary)

Root relaxation: objective 4.622366e+04, 253 iterations, 0.00 seconds

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

     0     0 46223.6640    0   88          - 46223.6640     -      -    0s
H    0     0                    72355.000000 46223.6640  36.1%     -    0s
H    0     0                    67387.000000 46223.6640  31.4%     -    0s
     0     0 56318.9377    0   18 67387.0000 56318.9377  16.4%     -    0s
     0     0 56645.1565    0   13 67387.0000 56645.1565  15.9%     -    0s
     0     0 56654.6313    0   11 67387.0000 56654.6313  15.9%     -    0s
H    0     0                    57366.000000 56654.6313  1.24%     -    0s
     0     2 56656.9091    0   11 57366.0000 56656.9091  1.24%     -    0s
H   27    26                    57339.000000 56656.9091  1.19%   4.0    0s
*  115    56              54    57118.000000 56681.7566  0.76%   4.1    0s
*  191    46              25    56888.000000 56698.5243  0.33%   4.0    0s
*  587   146              29    56884.000000 56751.5764  0.23%   4.2    0s
H  700   139                    56869.000000 56769.0914  0.18%   4.1    0s

Cutting planes:
  Gomory: 8
  Cover: 4
  Flow cover: 31
  Flow path: 7

Explored 784 nodes (3782 simplex iterations) in 0.34 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 5.686899999996e+04, best bound 5.686510598387e+04, gap 0.0068%