Build (method = -2) #dp: 25993 Step-3' Graph: 261 vertices and 776 arcs (0.20s) Step-4' Graph: 28 vertices and 310 arcs (0.20s) #V4/#V3 = 0.11 #A4/#A3 = 0.40 Ready! (0.20s) Optimize a model with 72 rows, 311 columns and 881 nonzeros Presolve removed 4 rows and 4 columns Presolve time: 0.00s Presolved: 68 rows, 307 columns, 871 nonzeros Variable types: 0 continuous, 307 integer (205 binary) Found heuristic solution: objective 31.0000000 Optimize a model with 68 rows, 307 columns and 871 nonzeros Presolved: 68 rows, 307 columns, 871 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 3.470e+02 Factor NZ : 8.730e+02 Factor Ops : 1.603e+04 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 3.76055970e+02 -8.01468752e+02 1.45e+02 4.88e-02 4.72e+00 0s 1 7.26551326e+01 -1.71188987e+02 7.07e+00 3.33e-16 5.21e-01 0s 2 2.09025883e+01 -2.17588971e+01 1.79e-13 2.78e-16 6.96e-02 0s 3 1.05158805e+01 1.29319853e+00 6.03e-13 6.44e-04 1.50e-02 0s 4 8.62089739e+00 7.14443752e+00 7.24e-14 1.01e-04 2.39e-03 0s 5 8.33813905e+00 8.32681651e+00 1.36e-13 1.20e-16 1.83e-05 0s 6 8.33333334e+00 8.33333332e+00 1.35e-13 1.32e-16 3.60e-11 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 8.33333334e+00 Root relaxation: objective 8.333333e+00, 238 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 8.33333 0 6 31.00000 8.33333 73.1% - 0s H 0 0 9.0000000 8.33333 7.41% - 0s Explored 0 nodes (402 simplex iterations) in 0.01 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 9.000000000000e+00, best bound 9.000000000000e+00, gap 0.0% Preprocessing time: 0.21 seconds Gurobi run time: 0.01 seconds Total run time: 0.22 seconds Objective: 9 Solution: 1 x [3, 11, 12, 16, 17, 18] 1 x [8, 14, 15, 18, 37] 1 x [4, 5, 9, 13, 31, 40] 1 x [1, 10, 20, 23, 25, 33] 1 x [1, 10, 19, 22, 24, 32] 1 x [7, 30, 39, 40, 42, 44] 1 x [6, 27, 29, 35, 38, 43] 1 x [2, 21, 26, 28, 34, 36] 1 x [32, 41, 41]