x, y, k, p = map(int, input().split())

res = x + y - k

def bob(): print("Bob"); exit()
def alice(): print("Alice"); exit()

if (res+1)//2 >= y:
    if y % 2 == 1 and p == -1: alice()
    if y % 2 == 0 and p == 1: alice()

if res//2 >= y:
    if y % 2 == 1 and p == 1: bob()
    if y % 2 == 0 and p == -1: bob()

if p==1: x -= 1
else: y -= 1

if res % 2 == 0: bob()


if min(x, y) >= res // 2:
    alice()


if x < y:
    if (res - x) % 2 == 0 and p == -1: alice()
    if (res - x) % 2 == 1 and p == 1: alice()

bob()