a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Tipo1 b c X X X X X d X X X X X X X X X X X X X X X a X Tipo3 b c d X X X X X X X X X X X X X X X X X X X 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 a X d X X X X X X X X X X X X X X X X X X X a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Tipo2 b c Tipo4 b c X X X d X X X X X X X X X X X X X X X X X