#include <bits/stdc++.h> using namespace std; typedef long long int ll; typedef pair<ll,ll> P; typedef vector<ll> VI; typedef vector<VI> VVI; #define REP(i,n) for(int i=0;i<(n);i++) #define ALL(v) v.begin(),v.end() template<typename T> bool chmax(T &x, const T &y) {return (x<y)?(x=y,true):false;}; template<typename T> bool chmin(T &x, const T &y) {return (x>y)?(x=y,true):false;}; constexpr ll MOD=998244353; constexpr ll INF=2e18; int main(){ ll x, y, k, p; cin >> x >> y >> k >> p; ll l=x+y-k; if(l/2<min(x,y)){ if(l%2==0) cout << "Bob" << endl; else cout << "Alice" << endl; } else{ if(y<x){ if(p==1) cout << "Alice" << endl; else cout << "Bob" << endl; } else{ if(k%2==(p==-1)) cout << "Alice" << endl; else cout << "Bob" << endl; } } return 0; }