Gurobi 5.0.1 (linux64) logging started Fri Jan 18 07:08:04 2013

Optimize a model with 68 rows, 4160 columns and 52122 nonzeros
Presolve removed 22 rows and 119 columns
Presolve time: 0.35s
Presolved: 46 rows, 4041 columns, 48080 nonzeros
Variable types: 4021 continuous, 20 integer (20 binary)

Root relaxation: objective 7.444602e+03, 22 iterations, 0.00 seconds

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

     0     0 7444.60178    0    8          - 7444.60178     -      -    0s
     0     0 7445.48886    0    8          - 7445.48886     -      -    0s
     0     0 7445.48886    0    8          - 7445.48886     -      -    0s
     0     2 7445.50020    0    8          - 7445.50020     -      -    1s
*   18    10              15    7470.4769159 7449.05915  0.29%   5.9    1s
*   41     9              11    7462.2444119 7458.57045  0.05%   4.9    1s
*   42     8              10    7460.7853828 7458.57045  0.03%   4.8    1s
*   55     4               8    7459.1542398 7458.75833  0.01%   4.2    1s

Cutting planes:
  Implied bound: 1
  Flow cover: 2

Explored 56 nodes (290 simplex iterations) in 1.45 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 7.459154239753e+03, best bound 7.458758326679e+03, gap 0.0053%