x, y, k, p = map(int, input().split())
if p == 1:
    p = 0
else:
    p = 1

r = x + y - k
d = r // 2
if d >= x:
    if k & 1 != p:
        print("Bob")
        exit()
if d >= y:        
    if p == 1:
        print("Bob")
        exit()
print("Alice")