#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ll X, Y, K, P;
    cin >> X >> Y >> K >> P;
    ll D = X + Y - K;

    bool ans; // trueならAlice勝ち
    if(X <= D / 2){
        ll Q;
        if(K % 2 == 0) Q = 1;
        else Q = -1;
        ans = (P == Q);
    }else if(Y <= D / 2){
        ll Q = 1;
        ans = (P == Q);
    }else{
        ans = (D % 2 == 1);
    }

    if(ans) cout << "Alice" << endl;
    else cout << "Bob" << endl;

    return 0;
}