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

r = x + y - k
def solve():
    d = r // 2

    if d >= x:
        if y & 1 != p & 1:
            return 1
    if d >= y:
        if p == 0:
            return 1
    return 0


if r & 1:
    ans = solve()
else:
    ans = 1 ^ solve()
if ans == 0:
    print("Alice")
else:
    print("Bob")