#include "prize.h"
#include <iostream>
#include <vector>
#ifdef _LOCAL_
#include "grader.cpp"
#endif // _LOCAL_
using namespace std;
int solve(int l, int r, vector <int> lRes, vector <int> rRes)
{
if(lRes==rRes) return -1;
if(l+1>=r) return -1;
int mid = (l+r)/2;
vector <int> midRes = ask(mid);
if(midRes==vector <int>{0, 0}) return mid;
else if(l==r) return -1;
int solL = solve(l, mid, lRes, midRes);
if(solL!=-1) return solL;
int solR = solve(mid, r, midRes, rRes);
return solR;
}
int find_best(int n)
{
vector <int> lRes = ask(0);
vector <int> rRes = ask(n-1);
if(lRes==vector <int>{0, 0}) return 0;
if(rRes==vector <int>{0, 0}) return n-1;
return solve(0, n-1, lRes, rRes);
}
