import sys,random,bisect from collections import deque,defaultdict from heapq import heapify,heappop,heappush from itertools import permutations from math import log,gcd input = lambda :sys.stdin.buffer.readline() mi = lambda :map(int,input().split()) li = lambda :list(mi()) X,Y,K,P = mi() A,B = (X+Y-K+1)//2,(X+Y-K)//2 if X <= A and pow(-1,Y) == P: exit(print("Alice")) if Y <= A and P == 1: exit(print("Alice")) if X <= B and pow(-1,Y) != P: exit(print("Bob")) if Y <= B and P == -1: exit(print("Bob")) if K&1: print("Alice") else: print("Bob")