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

desired_parity = 0 if P == 1 else 1
Y_initial_parity = Y % 2
s = Y_initial_parity ^ desired_parity  # XOR to find required parity of taken_Y

T = X + Y - K
a = max(0, T - X)
b = min(T, Y)

if a > b:
    print("Bob")
else:
    # Check if there's a number in [a, b] with parity s
    a_parity = a % 2
    b_parity = b % 2
    if (a_parity == s) or (b_parity == s) or (a_parity != b_parity):
        print("Alice")
    else:
        print("Bob")