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) or y <= 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")