change([Q,D,N,P]) :-
    member(Q, [0,1,2,3,4]),
    member(D, [0,1,2,3,4,5,6,7,8,9,10]),
    member(N, [0,1,2,3,4,5,6,7,8,9,10,
	       11,12,13,14,15,16,17,18,19,20]),
    S is 25*Q + 10*D + 5*N,
    S =< 100,
    P is 100-S.