#int(input())
#map(int, input().split())
#list(map(int, input().split()))

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

ans = 0

t = X + Y - K
a = t // 2 + t % 2
b = t // 2

if t % 2 == 1:
    if a <= min(X, Y):
        ans = 1
    elif X < a:
        if K % 2 == 0 and P == 1:
            ans = 1
        elif K % 2 == 1 and P == -1:
            ans = 1
        else:
            ans = 2
    else: # Y < a
        if P == 1:
            ans = 1
        else:
            ans = 2
else:
    if b < min(X, Y):
        ans = 2
    elif X <= b:
        if K % 2 == -P:
            ans = 1
        else:
            ans = 2
    else: # Y <= b
        if P == 1:
            ans = 1
        else:
            ans = 2

if ans == 1:
    print("Alice")
else:
    print("Bob")