Gurobi 5.6.3 (linux64) logging started Wed Oct  8 05:19:36 2014

Optimize a model with 54057 rows, 54056 columns and 161704 nonzeros
Presolve time: 1.41s
Presolved: 54057 rows, 54056 columns, 161704 nonzeros
Variable types: 0 continuous, 54056 integer (54056 binary)
Found heuristic solution: objective 23.9587095

Root relaxation: objective 1.538830e+01, 2866 iterations, 0.45 seconds

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

     0     0   15.38830    0  116   23.95871   15.38830  35.8%     -    2s
H    0     0                      15.4598068   15.38830  0.46%     -    2s
H    0     0                      15.4412170   15.38830  0.34%     -    2s
H    0     0                      15.4139184   15.38830  0.17%     -    2s
     0     0   15.39132    0  146   15.41392   15.39132  0.15%     -    2s
     0     0   15.39132    0   20   15.41392   15.39132  0.15%     -    2s
     0     0   15.39592    0   23   15.41392   15.39592  0.12%     -    2s
H    0     0                      15.3962423   15.39592  0.00%     -    2s

Cutting planes:
  Gomory: 1

Explored 0 nodes (3259 simplex iterations) in 2.94 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 1.539624225591e+01, best bound 1.539592007329e+01, gap 0.0021%