#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 3000000000000000

int main(){
	
	int X,Y,K,P;
	cin>>X>>Y>>K>>P;
	int turns = X+Y-K;
	
	int need = 0;
	if(Y%2==1)need = 1;
	if(P==-1)need ^= 1;

	int E;
	if(need==0){
		E = min(turns-1,Y);
		
		
	}
	else{
		E = min(turns,Y);
	}
	//cout<<E<<','<<need<<endl;
	if(E%2==need)cout<<"Alice"<<endl;
	else cout<<"Bob"<<endl;
	
	return 0;
}