x, y, k, p = map(int, input().split())
z = x+y-k
if z%2:
    if p == 1: print("Bob" if k%2 and x <= z//2 else "Alice")
    else: print("Bob" if not k%2 and x <= z//2 or y <= z//2 else "Alice")
else:
    if p == 1: print("Alice" if not k%2 and x <= z//2 or y <= z//2 else "Bob")
    else: print("Alice" if k%2 and x <= z//2 else "Bob")