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

if P == 1:
    t = 0
else:
    t = 1
D = (Y - t) % 2

E_min = max(0, N - X)
E_max = min(Y, N)

if E_min > E_max:
    print("Bob")
else:
    can = False
    if (E_min % 2 == D) or (E_max % 2 == D):
        can = True
    else:
        if (E_min % 2 != E_max % 2) and (E_min <= E_max):
            can = True
    if not can:
        print("Bob")
    else:
        if (E_min % 2 == D) and (E_max % 2 == D):
            print("Alice")
        else:
            if N % 2 == 1:
                print("Alice")
            else:
                print("Bob")