import sys
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
li = lambda: list(mi())
inf = 2 ** 63 - 1
mod = 998244353

x, y, k, p = mi()

if y % 2:
    p = -p
k = (x + y - k)

if y <= (k + 1) // 2 and (-1) ** y == p:
    print('Alice')
    exit()
if x <= (k + 1) // 2 and (-1) ** (k - x) ==p:
    print('Alice')
    exit()

if y <= k // 2 and (-1) ** y != p:
    print('Bob')
    exit()
if x <= k // 2 and (-1) ** (k - x) != p:
    print('Bob')
    exit()

if k % 2:
    print('Alice')
else:
    print('Bob')