X,Y,K,P = map(int,input().split())

A = "Alice"
B = "Bob"
import sys

u = X + Y - K
if u % 2 == 1:
    a = u // 2 + 1
else:
    a = u // 2
b = u // 2
if Y % 2 == 1:
    t = -1
else:
    t = 1

if X <= a:
    if K % 2 == 1 and P == -1:
        print(A)
        exit()
    if K % 2 == 0 and P == 1:
        print(A)
        exit()
if Y <= a:
    if P == 1:
        print(A)
        exit()

if X <= b:
    if K % 2 == 1 and P == 1:
        print(B)
        exit()
    if K % 2 == 0 and P == -1:
        print(B)
        exit()
if Y <= b:
    if P == -1:
        print(B)
        exit()

        



        
    

        
if u % 2 == 0:
    print(B)
else:
    print(A)