#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;
 
int main(){
  ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  
  ll x,y,k,p;
  cin>>x>>y>>k>>p;
  ll z=x+y-k;
  
  if(p==1){
    if((z+1)/2>=y) cout<<"Alice"<<endl;
    else if((z+1)/2>=x && k%2==0) cout<<"Alice"<<endl;
    else if(z%2==0) cout<<"Bob"<<endl;
    else cout<<"Alice"<<endl;
  }
  else if(p==-1){
    if(z/2>=y) cout<<"Bob"<<endl;
    else if(z/2>=x && k%2==0) cout<<"Bob"<<endl;
    else if(z%2==0) cout<<"Bob"<<endl;
    else cout<<"Alice"<<endl;
  }
  
  return 0;
}