#pragma GCC optimize("Ofast")
#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <queue>
#include <cstdio>
#include <ctime>
#include <assert.h>
#include <chrono>
#include <random>
#include <numeric>
#include <set>
#include <deque>
#include <stack>
#include <sstream>
#include <utility>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
#include <tuple>
#include <array>
#include <bitset>
using namespace std;
typedef long long int ll;
typedef unsigned long long ull;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll myRand(ll B) {
    return (ull)rng() % B;
}
inline double time() {
    return static_cast<long double>(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count()) * 1e-9;
}

bool solve(){
    int x,y,k,p; cin >> x >> y >> k >> p;
    int u = (p==-1?1:0);
    int pick = x+y-k;
    if(u == 0){
        // -1を全て消化
        if((pick+1)/2 >= y) return true;
        if(pick/2 >= x and k%2 != u) return false;
        if((pick+1)/2 >= x and k%2 == u) return true;
        else{
            return (pick%2 == 1);
        }
    }
    assert(0);     
    return false;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    if(solve()){
        cout << "Alice" << endl;
    }
    else{
        cout << "Bob" << endl;
    }
}