Build (method = -2) #dp: 744 Step-3' Graph: 59 vertices and 168 arcs (0.00s) Step-4' Graph: 6 vertices and 62 arcs (0.00s) #V4/#V3 = 0.10 #A4/#A3 = 0.37 Ready! (0.00s) Optimize a model with 25 rows, 63 columns and 183 nonzeros Presolve removed 2 rows and 2 columns Presolve time: 0.00s Presolved: 23 rows, 61 columns, 179 nonzeros Variable types: 0 continuous, 61 integer (3 binary) Found heuristic solution: objective 197.0000000 Optimize a model with 23 rows, 61 columns and 179 nonzeros Presolved: 23 rows, 61 columns, 179 nonzeros Root barrier log... Ordering time: 0.00s Barrier statistics: AA' NZ : 6.400e+01 Factor NZ : 2.760e+02 Factor Ops : 4.324e+03 (less than 1 second per iteration) Threads : 1 Objective Residual Iter Primal Dual Primal Dual Compl Time 0 6.46335080e+02 -5.45905093e+02 7.45e+01 2.27e-02 2.33e+01 0s 1 1.58405762e+02 -2.40043448e+02 2.71e+00 2.22e-16 3.30e+00 0s 2 8.82283946e+01 2.33782666e+01 6.34e-03 6.33e-15 4.67e-01 0s 3 6.73385731e+01 6.28545656e+01 1.33e-14 4.44e-16 3.20e-02 0s 4 6.66876362e+01 6.65806395e+01 3.10e-14 3.33e-16 7.64e-04 0s 5 6.66666703e+01 6.66666569e+01 6.40e-14 2.86e-16 9.57e-08 0s 6 6.66666667e+01 6.66666667e+01 2.10e-14 2.22e-16 9.82e-14 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 6.66666667e+01 Root relaxation: objective 6.666667e+01, 48 iterations, 0.00 seconds Nodes | Current Node | Objective Bounds | Work Expl Unexpl | Obj Depth IntInf | Incumbent BestBd Gap | It/Node Time 0 0 66.66667 0 4 197.00000 66.66667 66.2% - 0s H 0 0 67.0000000 66.66667 0.50% - 0s Explored 0 nodes (68 simplex iterations) in 0.00 seconds Thread count was 1 (of 8 available processors) Optimal solution found (tolerance 0.00e+00) Best objective 6.700000000000e+01, best bound 6.700000000000e+01, gap 0.0% Preprocessing time: 0.01 seconds Gurobi run time: 0.00 seconds Total run time: 0.01 seconds Objective: 67 Solution: 2 x [3, 13, 18] 3 x [10, 12, 16] 1 x [3, 4, 7] 5 x [4, 5, 11] 15 x [8, 10, 16] 12 x [3, 14, 17] 1 x [10, 13] 10 x [1, 6, 11] 1 x [1, 2, 13] 12 x [9, 15, 19] 2 x [6, 11, 13] 2 x [13, 17, 19] 1 x [2, 13, 19]