#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int num = 0;
#define sz(a) (int)(a.size());
int solve(int l,int r,int lf = 0,int rg = 0){
//cout<<l<<" "<<r<<'\n';
if(l > r)return -1;
int mid = (l+r)/2;
int i = 0;
vector<int>res;
for(i=mid;i<=r;i++){
res = ask(i);
if(!res[0] && !res[1])return i;
else if(res[0] + res[1] == num)break;
}
if(i<=r){
if(res[1]-rg){
int c = solve(i+1,r,res[0],rg);
if(c!=-1)return c;
}
if(res[0]-lf){
int c = solve(l,mid-1,lf,res[1]);
if(c!=-1)return c;
}
return -1;
}else{
for(i=mid-1;i>=l;i--){
res = ask(i);
if(!res[0] && !res[1])return i;
else if(res[0] + res[1] == num)break;
}
if(i>=l && res[0]-lf)return solve(l,i-1,lf,res[1]);
else return -1;
}
}
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int find_best(int n) {
for(int i=0;i<10;i++){ //random until find dao biggest guy
int c = uniform_int_distribution<int>(0,n-1)(rng);
vector<int>res = ask(c);
num = max(num,res[0]+res[1]);
}
//d&c to try all small guys since < #small guys < sqrt(n)
int ans = solve(0,n-1);
assert(ans!=-1);
return ans;
}
