/*
Code by @marlov
*/
#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <utility>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <stack>
#include <queue>
#include <iterator>
#include <bitset>
#include "prize.h"
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
int N;
int sN;
int mvs=0;
int result=0;
/*
vector<int> ask(int i){
cout<<"query: "<<i<<endl;
int rlv,rrv;
cin>>rlv>>rrv;
return {rlv,rrv};
}
*/
unordered_map<int,int> lv;
unordered_map<int,int> rv;
vector<int> query(int i){
if(!(lv.count(i)==1&&rv.count(i)==1)){
vector<int> askv=ask(i);
lv[i]=askv[0];
rv[i]=askv[1];
}
if(lv[i]+rv[i]==0) result=i;
return {lv[i],rv[i]};
}
void binary_search(int l,int r){
//cout<<"seeing:"<<l<<","<<r<<endl;
if(l==r) return;
vector<int> lb=query(l);
vector<int> rb=query(r);
if(lb[0]+lb[1]<mvs) binary_search(l+1,r);
if(rb[0]+rb[1]<mvs) binary_search(l,r-1);
int mid=(l+r)/2;
if(rb[0]-lb[0]==0) return;
binary_search(l,mid);
binary_search(mid+1,r);
}
//method can use int[] ask(int i) which return left and right value
int find_best(int n){
int N=n;
int sN=ceil(sqrt((double)N));
//loop first sqrtN value to find max dude
for(int i=0;i<sN;i++){
vector<int> qv=query(i);
mvs=max(mvs,qv[0]+qv[1]);
}
//loop through sqrtN
for(int i=0;i<N;i+=sN){
binary_search(i,(i+sN<N?i+sN:N-1));
}
return result;
}
/*
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int val=find_best(8);
cout<<"ANSWER:"<<val<<endl;
return 0;
}
*/
/* stuff you should look for
* int overflow, array bounds
* special cases (n=1,n=0?)
* do smth instead of nothing and stay organized
*/
