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

T = X + Y - K

# Compute S_req
c = 0 if P == 1 else 1
S_req = (Y - c) % 2

# Compute the required parity of F (number of -1's eaten)
# F mod 2 must be (S_req - Y) mod 2
required_sum = (S_req - Y) % 2

# Determine if Alice can win
if required_sum == 0:
    print("Alice")
else:
    print("Bob")