1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Map(1 -> 1) 1 Map(1 -> 1) 1 (1,1) Map(1 -> 1) 1 (1,1) Map(1 -> 1) 1 (1,2) Map(1 -> 2) 2 (1,2) Map(1 -> 2) 2