X,Y,K,P = map(int,input().split())
cnt = X+Y-K #引く回数
A_cnt = cnt//2+cnt%2
B_cnt = cnt//2
if P==1:
    if A_cnt >= Y: print("Alice");exit()
    if cnt == 1 and Y%2==0: print("Bob");exit()
    if B_cnt >= X: print("Alice");exit()
    if A_cnt == B_cnt: print("Bob");exit()
    else:print("Alice");exit()

else:
    if B_cnt >= Y: print("Bob");exit()
    if cnt == 1 and Y%2==1: print("Bob");exit()
    if B_cnt >= X: print("Alice");exit()
    if A_cnt == B_cnt: print("Bob");exit()
    else:print("Alice");exit()