#include "prize.h"
#include<bits/stdc++.h>
using namespace std;
vector< pair<int,int> > v;
int sum;
int ans;
void recur(int l, int r) {
if(ans!=-1) return;
if(l>r) return;
int mid = (l+r)/2;
for(int i=mid; i<=r; i++) {
vector<int> tmp = ask(i);
if(tmp[0]+tmp[1] > sum) {
recur(l, mid-1);
recur(i+1, r);
return;
} else {
v.push_back({tmp[0]+tmp[1], i});
if(tmp[0]+tmp[1]==0) {
ans=i;
return;
}
}
}
for(int i=mid-1; i>=l; i--) {
vector<int> tmp = ask(i);
if(tmp[0]+tmp[1] > sum) {
recur(l, i-1);
return;
} else {
v.push_back({tmp[0]+tmp[1], i});
if(tmp[0]+tmp[1]==0) {
ans=i;
return;
}
}
}
}
int find_best(int n) {
if(n<=5000) {
for(int i=0; i<n; i++) {
vector<int> tmp = ask(i);
if(tmp[0]+tmp[1]==0) return i;
}
}
sum = 0;
for(int tmp=sqrt(sqrt(n)); tmp>=2; tmp=sqrt(tmp)) {
sum += tmp;
}
sum++;
ans = -1;
recur(0, n-1);
return ans;
}
