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

min_neg = max(0, K - X)
max_neg = min(Y, K)
desired_parity = 0 if P == 1 else 1

# Check if there exists a number with desired parity in [min_neg, max_neg]
exists = False
if min_neg <= max_neg:
    first_candidate = min_neg if (min_neg % 2 == desired_parity) else (min_neg + 1)
    if first_candidate <= max_neg:
        exists = True

if not exists:
    print("Bob")
else:
    # Check the condition for Alice's win
    condition = (min_neg % 2 == desired_parity) or (max_neg % 2 == desired_parity) or (min_neg % 2 != max_neg % 2)
    if condition:
        print("Alice")
    else:
        print("Bob")