Gurobi 5.0.1 (linux64) logging started Fri Jan 18 07:08:01 2013

Optimize a model with 68 rows, 4160 columns and 52122 nonzeros
Presolve removed 22 rows and 122 columns
Presolve time: 0.31s
Presolved: 46 rows, 4038 columns, 48074 nonzeros
Variable types: 4018 continuous, 20 integer (20 binary)

Root relaxation: objective 4.440467e+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 4440.46714    0    8          - 4440.46714     -      -    0s
     0     0 4441.57853    0    8          - 4441.57853     -      -    0s
     0     0 4441.57853    0    8          - 4441.57853     -      -    0s
     0     2 4443.47937    0    8          - 4443.47937     -      -    1s
*  231    53              17    4467.6787604 4446.58556  0.47%   1.9    1s
H  289    28                    4460.1213764 4448.80881  0.25%   2.2    1s
*  371    11              14    4459.9384688 4457.87136  0.05%   2.7    1s
H  372     6                    4458.9449856 4457.87136  0.02%   2.7    1s

Cutting planes:
  Implied bound: 10
  Flow cover: 2

Explored 383 nodes (1116 simplex iterations) in 1.85 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 4.458944985629e+03, best bound 4.458523383534e+03, gap 0.0095%