import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

def f(x,y,k,p,z):
    if x + y < k:
        return "-"
    if k == x + y:
        if p == [1,-1][y%2]:
            return 1
        return 0
    if z:
        res = 0
        if x:
            res |= f(x-1, y, k, p, 0)
        if y:
            res |= f(x, y-1, k, p, 0)
        return res
    else:
        res = 1
        if x:
            res &= f(x-1, y, k, p, 1)
        if y:
            res &= f(x, y-1, k, p, 1)
        return res

def solve(x,y,k,p):
    if p == 1:
        if y <= (x + y - k  + 1)//2:
            ans = 1
        elif (x + y - k) % 2:
            ans = 1
        else:
            ans = 0
    else:
        if y <= (x + y - k)//2:
            ans = 0
        elif (x + y - k) % 2:
            ans = 1
        else:
            ans = 0
    return ans

def solve(x,y,k,p):
    if p == 1:
        if k % 2:
            if x - y >= k:
                return 1
            elif y - x >= k:
                return 0
            elif (x + y)%2 == 0:
                return 1
            else:
                return 0
        else:
            if x - y >= k:
                return 1
            elif y - x >= k:
                return 1
            elif (x + y)%2 == 0:
                return 0
            else:
                return 1
    else:
        if k % 2:
            if y - x >= k:
                return 1
            elif x-y >= k:
                return 0
            elif (x + y)%2 == 0:
                return 1
            else:
                return 0
        else:
            if y - x >= k:
                return 0
            elif x - y >= k:
                return 0
            elif (x + y)%2 == 0:
                return 0
            else:
                return 1


x,y,k,p = na()
ans = solve(x,y,k,p)
if ans:
    print("Alice")
else:
    print("Bob")
"""
from random import randint
for _ in range(100):
    x,y = randint(1,8),randint(1,8)
    k = randint(1, x + y - 1)
    p = [-1,1][randint(0,1)]
    a1 = f(x,y,k,p,1)
    a2 = solve(x,y,k,p)
    if a1 != a2:
        print(x,y,k,p,a1,a2)"""

"""a = [[[f(x,y,k,-1,1) for y in range(1,10)]for x in range(1,10)]for k in range(1,20)]
for i in a:
    for j in i:
        print(*j)
    print()"""