#include <iostream>
using namespace std;
using ll=long long;

void Alice(){
    cout << "Alice" << "\n";
}
void Bob(){
    cout << "Bob" << "\n";
}
int main(void){
    ll x,y,k,p;
    cin >> x >> y >> k >> p;
    ll aT = (x+y-k+1)/2;
    ll bT = x+y-k-aT;
    if(p == -1){
        if(bT >= y){
            Bob();
            return 0;
        }else if(k % 2 == 1){
            Alice();
            return 0;
        }
    }else if(p == 1){
        if(aT >= y){
            Alice();
            return 0;
        }else if(k % 2 == 0){
            Bob();
            return 0;
        }
    }
    if(aT == bT) Bob();
    else Alice();
    return 0;
}