#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int num = 0;
#define sz(a) (int)(a.size());
vector<int>res[200000];
int cnt = 0;
int solve(int l,int r,int lf = 0,int rg = 0){
if(l > r)return -1;
int mid = (l+r)/2;
for(int i=0;i<=r-l;i++){
if(i%2==0){
int m = mid-i/2;
res[m] = ask(m);
if(!res[m][0] && !res[m][1])return m;
else if(res[m][0] + res[m][1] == num){
int c = -1;
if(res[m][0]-lf > 0)c = max(c,solve(l,m-1,lf,res[m][1]));
m = mid+(i+1)/2;
if(res[m][1]-rg > 0)c = max(c,solve(m+1,r,res[m][0],rg));
if(c!=-1)return c;
break;
}
}else{
int m = mid+(i+1)/2;
res[m] = ask(m);
if(!res[m][0] && !res[m][1])return m;
else if(res[m][0] + res[m][1] == num){
int c = -1;
if(res[m][1]-rg > 0)c = max(c,solve(m+1,r,res[m][0],rg));
m = mid + i/2;
if(res[m][0]-lf > 0)c = max(c,solve(l,m-1,lf,res[m][1]));
if(c!=-1)return c;
break;
}
}
}
return -1;
}
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int find_best(int n) {
for(int i=0;i<50;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]);
if(!res[0] && !res[1])return c;
}
//d&c to try all small guys since < #small guys < sqrt(n)
return solve(0,n-1);
}
