hanoi(N, I) :-
move(N, a, b, c, I).
move(N, A, B, C, I) :-
N > 1, N1 is N-1,
move(N1, A, C, B, I1),
move(1, A, B, C, 1),
move(N1, C, B, A, I2),
I is I1 + I2 + 1.
move(1, A, B, _, 1) :-
write(A),write(' to '),write(B),nl.