x,y,k,p=list(map(int,input().split()))
d=x+y-k
if d//2>=y:
    if p==1:
        print("Alice")
    else:
        print("Bob")
elif d//2>=x:
    if pow(-1,k)==p:
        print("Alice")
    else:
        print("Bob")
elif d%2==0:
    print("Bob")
else:
    print("Alice")