x, y, k, p = map(int, input().split()) z = x + y - k if z % 2 == 1: if p == 1: if k % 2 == 1 and x <= z // 2: print("Bob") else: print("Alice") else: if k % 2 == 0 and x <= z // 2: print("Bob") else: print("Alice") else: if p == 1: if (k % 2 == 0 and x <= z // 2) or y <= z // 2: print("Alice") else: print("Bob") else: if k % 2 == 1 and x <= z // 2: print("Alice") else: print("Bob")