#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    ll X,Y,K,P; cin >> X >> Y >> K >> P;
    ll S = (Y % 2 == 0 ? +1 : -1);
    ll T = P / S;
    ll U = (X + Y - K);
    if(T == +1) {
        cout << ((X + Y + max(0LL, X - U + 1)) % 2 == 0 ? "Alice" : "Bob") << endl;
    } else {
        cout << ((X + Y + max(0LL, Y - U + 1)) % 2 == 0 ? "Alice" : "Bob") << endl;
    }
}