Build (method = -2) #dp: 930 Step-3' Graph: 60 vertices and 171 arcs (0.00s) Step-4' Graph: 6 vertices and 63 arcs (0.00s) #V4/#V3 = 0.10 #A4/#A3 = 0.37 Ready! (0.00s) Optimize a model with 25 rows, 64 columns and 186 nonzeros Presolve removed 2 rows and 2 columns Presolve time: 0.00s Presolved: 23 rows, 62 columns, 182 nonzeros Variable types: 0 continuous, 62 integer (3 binary) Found heuristic solution: objective 198.0000000 Found heuristic solution: objective 184.0000000 Optimize a model with 23 rows, 62 columns and 182 nonzeros Presolved: 23 rows, 62 columns, 182 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 6.31024844e+02 -5.45328744e+02 7.22e+01 2.71e-02 2.26e+01 0s 1 1.55425379e+02 -2.34797428e+02 2.47e+00 4.44e-16 3.16e+00 0s 2 8.82715286e+01 2.28902510e+01 1.96e-02 6.11e-16 4.65e-01 0s 3 6.72670453e+01 6.25940037e+01 3.61e-05 1.11e-16 3.29e-02 0s 4 6.66862741e+01 6.65733582e+01 3.60e-14 3.33e-16 7.95e-04 0s 5 6.66666675e+01 6.66666590e+01 1.12e-14 2.22e-16 5.95e-08 0s 6 6.66666667e+01 6.66666667e+01 3.69e-14 1.94e-16 6.14e-14 0s Barrier solved model in 6 iterations and 0.00 seconds Optimal objective 6.66666667e+01 Root relaxation: objective 6.666667e+01, 51 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 4 184.00000 66.66667 63.8% - 0s H 0 0 67.0000000 66.66667 0.50% - 0s Explored 0 nodes (63 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: 15 x [2, 8, 9] 2 x [6, 15, 17] 4 x [6, 11, 16] 14 x [1, 2, 16] 3 x [5, 13, 17] 7 x [14, 17, 19] 1 x [6, 17, 18] 2 x [11, 17, 19] 7 x [7, 12, 18] 10 x [3, 4, 13] 1 x [12, 18] 1 x [3, 10, 13]