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

E = X + Y - K

desired_parity = 0 if P == 1 else 1
target_b_parity = (Y - desired_parity) % 2

b_min = max(0, E - X)
b_max = min(Y, E)

possible_parity = False

if b_min <= b_max:
    if (b_min % 2 == target_b_parity) or (b_max % 2 == target_b_parity):
        possible_parity = True
    else:
        if (b_max - b_min) >= 1:
            possible_parity = True

if not possible_parity:
    print("Bob")
else:
    if E % 2 == 1:
        print("Alice")
    else:
        if (b_min % 2 == b_max % 2):
            if (b_min % 2 == target_b_parity):
                print("Alice")
            else:
                print("Bob")
        else:
            print("Bob")