pa(X,Y):-pored_d(X,Y).
pa(X,Y):-pored_d(X,Z),pa(Z,Y).
pb(X,Y):-pa(X,Y),godina_rodjenja(X,G), godina_rodjenja(Y,G).
pc(X,Y,Z):-pa(Y,X),pa(Z,X),not(Y=Z).


cifra(0,nula).
cifra(1,jedan).
cifra(2,dva).
cifra(3,tri).
cifra(4,cetiri).
cifra(5,pet).
cifra(6,sest).
cifra(7,sedam).
cifra(8,osam).
cifra(9,devet).

ispis(0).
ispis(N):- C is N mod 10, cifra(C,X),write(X),write(' '),N1 is N//10,ispis(N1).

ispisObr(0).
ispisObr(N):-N1 is N//10,ispisObr(N1),C is N mod 10, cifra(C,X),write(X),write(' ').


cifra(0).
cifra(1).
cifra(2).
cifra(3).
cifra(4).
cifra(5).
cifra(6).
cifra(7).
cifra(8).
cifra(9).

resi(S,N,E,G,A,K,P,O,R,T) :- cifra(S),S=\=0,
	cifra(N),N=\=S,
	cifra(E),E=\=N,E=\=S,
	cifra(G),G=\=E,G=\=N,G=\=S,
	cifra(A),A=\=G,A=\=E,A=\=N,A=\=S,
	cifra(K),K=\=A,K=\=G,K=\=E,K=\=N,K=\=S,
	cifra(P),P=\=K,P=\=A,P=\=G,P=\=E,P=\=N,P=\=S,
	cifra(O),O=\=P,O=\=K,O=\=A,O=\=G,O=\=E,O=\=N,O=\=S,
	cifra(R),R=\=O,R=\=P,R=\=K,R=\=A,R=\=G,R=\=E,R=\=N,R=\=S,
	cifra(T),T=\=R,T=\=O,T=\=P,T=\=K,T=\=A,T=\=G,T=\=E,T=\=N,T=\=S,
	suma(S,N,E,G,A,K,P,O,R,T).


suma(S,N,E,G,A,K,P,O,R,T):- 1000*S+100*N+10*E+G + 10000*S+1000*A+100*N+10*K+E =:= S*10000+P*1000+O*100+R*10+T.




elem(X,[X|_]).
elem(X,[Y|R]):- X=\=Y,elem(X,R).

sadrzi(X, [X|_]).
sadrzi(X, [G|R]):- G \== X,
                    sadrzi(X, R).


razresi(L):- L=[[_,andric,torta],[_,brankovic,_],[_,davidovic,_],[_,_,_]],
			sadrzi([ruska,_,kafa],L),
			sadrzi([vladislava,_,_],L),
			sadrzi([ana,petrovic,_],L),
			sadrzi([marija,_,_],L),
			sadrzi([_,_,vino],L),
			sadrzi([_,_,kolac],L),
			\+(sadrzi([_,brankovic,kolac],L)),
			\+(sadrzi([vladislava,_,kolac],L)),
			\+(sadrzi([ruska,davidovic,_],L)),
			\+(sadrzi([marija,_,vino],L)).
sredi([],[]).
sredi([G|R],L):-sredi(R,R1), dodaj(G,R1, L).
dodaj(X,[],[s(X,1)]).
dodaj(X,[s(X,B)|R],[s(X,B1)|R]):-B1 is B+1,!.
dodaj(X,[s(G,B)|R],[s(X,1), s(G,B)|R]):-X<G,!.
dodaj(X,[s(G,B)|R],[ s(G,B)|R1]):-dodaj(X,R,R1).



duzina([],0).
duzina([_|R],N):-duzina(R,N1),N is N1+1.

suma(_,0,0).
suma([G|R],K,S):-K>0, K1 is K-1, suma(R,K1,S1), S is S1+G.
suma_k(L,K,[]):-duzina(L,D), D<K.
suma_k([G|R],K,[S|R1]):-suma([G|R],K,S), suma_k(R,K,R1).


istree(nil).
istree(t(_,L,R)) :- istree(L), istree(R).

add(X,nil,t(X,nil,nil)).
add(X,t(Root,L,R),t(Root,L1,R)) :- X =< Root, add(X,L,L1).
add(X,t(Root,L,R),t(Root,L,R1)) :- X > Root, add(X,R,R1).

napravi(L,T) :- napravi(L,T,nil).

napravi([],T,T).
napravi([N|Ns],T,T0) :- add(N,T0,T1), napravi(Ns,T,T1).

leaves1(nil,[]).
leaves1(t(X,nil,nil),[X]) :- !.
leaves1(t(_,L,R),S) :-
    leaves1(L,SL), leaves1(R,SR), append(SL,SR,S).