X,Y,K,P=map(int,input().split()) toru=X+Y-K if toru%2==0: if X<=toru//2: if K%2==0 and P==1: print("Alice") exit() if K%2==1 and P==-1: print("Alice") exit() if Y<=toru//2: if P==1: print("Alice") exit() print("Bob") else: if X<=(toru-1)//2: if K%2==0 and P==-1: print("Bob") exit() if K%2==1 and P==1: print("Bob") exit() if Y<=(toru-1)//2: if P==-1: print("Bob") exit() print("Alice")