c c This is a simple example file to demonstrate the c DIMACS input file format for minimum-cost flow problems. c c problem line : p min 4 5 c c node descriptor lines : n 1 4 n 4 -4 c c arc descriptor lines : a 1 2 0 4 2 a 1 3 0 2 2 a 2 3 0 2 1 a 2 4 0 3 3 a 3 4 0 5 1