matrix(S, M) :-
	length(M, S),
	matrix1(M, S).

matrix1([], _).
matrix1([H|T], S) :-
	length(H, S),
	matrix1(T, S).

next(A, B, A, B).
next(1, 0, 0, 1).
next(0, 1, -1, 0).
next(-1, 0, 0, -1).
next(0, -1, 1, 0).

solve(N, M) :-
	N2 is N*N,
	numlist(1, N2, L),
	matrix(N, M),
	solve(L, -1, 0, 1, 0, M).

solve([], _, _, _, _, _).

solve([Ix|T], X, Y, Dx, Dy, M) :-
	next(Dx, Dy, Dx1, Dy1),
	Y1 is Y+Dy1,
	X1 is X+Dx1,
	nth0(Y1, M, Row),
	nth0(X1, Row, Ix),
	!,
	solve(T, X1, Y1, Dx1, Dy1, M).

:- solve(5, M), writeln(M).