abs(N,N):-N>=0,!.
abs(N,X):-N<0,X is -N.

nzd(X,0,X):-!.
nzd(X,Y,Z):- X>Y,N is X-Y,nzd(N,Y,Z),!.
nzd(X,Y,Z):- X=<Y,N is Y-X,nzd(N,X,Z),!.

nzs(X,Y,Z):- nzd(X,Y,P),Z is (X*Y)/P,!.

fib(0,1):-!.
fib(1,1):-!.

fib(N,X):-N1 is N-1,N2 is N-2,fib(N1,X1),fib(N2,X2),X is X1+X2.

brisi(_,[],[]):-!.
brisi(X,[X|R],R):-!.
brisi(X,[Y|L],[Y|R]):-brisi(X,L,R).

brisi_sve(_,[],[]):- !.
brisi_sve(X,[X|R],R1):-brisi_sve(X,R,R1),!.
brisi_sve(X,[Y|R],[Y|R1]):-brisi_sve(X,R,R1).


ubaci_na_kraj(X, [], [X]).
ubaci_na_kraj(X, [G|R], [G|R1]):- ubaci_na_kraj(X, R, R1).

rotiraj(L, 0, L).
rotiraj([G|R], N, L):- ubaci_na_kraj(G, R, R1),
                       N1 is N - 1,
                       rotiraj(R1, N1, L).