“…The first test set contains 260 random problems of different complexities. It consists of 13 subsets of 20 problems: (1, 3, 5), (2,5,10), (4,7,15), (5, 10, 20), (7,12,25), (9,15,30), (10,17,35), (12,20,40), (13,22,45), (14,25,50), (15,27,55) and (16,30,60), where (pl, c, p) refers to number of planes (pl), number of cities (c) and number of persons and goals (p). All these problems have seven levels of fuel.…”