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

r = x + y - k
if r & 1:
    d = r // 2
    if d >= x:
        if k & 1 != p:
            print("Bob")
            exit()
    if d >= y:        
        if p == 1:
            print("Bob")
            exit()
    print("Alice")
else:
    d = r // 2
    if d >= x:
        if k & 1 == p:
            print("Alice")
            exit()
    if d >= y:        
        if p == 0:
            print("Alice")
            exit()
    print("Bob")