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

d = 0 if P == 1 else 1

s_min = max(0, K - X)
s_max = min(Y, K)

# Check if there's any s in [s_min, s_max] with parity d
has_d_parity = False
# The minimum and maximum possible s values. If any of them or any in between has parity d.
low = s_min
high = s_max
if low > high:
    has_d_parity = False
else:
    if low % 2 == d or high % 2 == d:
        has_d_parity = True
    else:
        # Check if there are elements with parity d between low and high
        if low < high:
            has_d_parity = True

if not has_d_parity:
    print("Bob")
    exit()

r = (Y - d) % 2

M = X + Y - K

a_min = max(0, M - X)
a_max = min(Y, M)

# Check if there exists a in [a_min, a_max] with parity r
valid_r = False
if a_min > a_max:
    valid_r = False
else:
    # Check a_min and a_max first
    if a_min % 2 == r or a_max % 2 == r:
        valid_r = True
    else:
        # If there's at least one a between a_min and a_max with parity r
        # The difference between a_min and a_max >=1 and they have different parities
        # then there's a a with parity r in between.
        if a_min < a_max:
            valid_r = True

if not valid_r:
    print("Bob")
    exit()

if M % 2 == 1:
    print("Alice")
else:
    # Check if there exists a in [a_min, a_max] with parity (r ^ 1)
    valid_opposite = False
    if a_min <= a_max:
        # Check a_min and a_max first
        if a_min % 2 == (r ^ 1) or a_max % 2 == (r ^ 1):
            valid_opposite = True
        else:
            # Check if there are any elements in between
            if a_min < a_max:
                valid_opposite = (a_min % 2 != a_max % 2)

    if valid_opposite:
        print("Bob")
    else:
        print("Alice")