#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
typedef vector<int> vi;
const int MX=200010;
bool up[MX];
int L[MX], R[MX], sum, n, ans;
void my_ask(int i){
if(L[i]>=0) return;
vi now=ask(i);
L[i]=now[0], R[i]=now[1];
}
void search(int s, int e, int lc, int mc, int rc){
if(s>e || mc==0) return;
assert(mc>=0);
int m=(s+e)/2;
for(int i=m; i<=e; i++){
my_ask(i);
if(L[i]+R[i]==0){ ans=i; return; }
if(L[i]+R[i]==sum){
search(s,m-1, lc, L[i]-(i-m)-lc, R[i]+i-m);
search(i+1,e, L[i], R[i]-rc, rc);
return;
}
}
for(int i=m; i>=s; i--){
my_ask(i);
if(L[i]+R[i]==0){ ans=i; return; }
if(L[i]+R[i]==sum){
search(s,i-1, lc, L[i]-lc, R[i]);
return;
}
}
}
void get(){
for(int i=0; i<min(n,500); i++){
my_ask(i);
sum=max(sum, L[i]+R[i]);
}
}
int find_best(int _n){
n=_n;
for(int i=0; i<n; i++) L[i]=R[i]=-1;
get();
ans=-1;
search(0,n-1,0,sum,0);
assert(ans>=0 && L[ans]==0 && R[ans]==0);
return ans;
}
