//#include "prize.h"
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
static const int max_q = 10000;
static int n;
static int query_count = 0;
static vector<int> g;
static vector<vector<int> > rank_count;
int find_best(int n);
std::vector<int> ask(int i);
int subtask1(int n){
int start=0, end=n-1;
while (start<end) {
int mid = (start+end)/2;
vector<int> ans = ask(mid);
if (!ans[0] && !ans[1]) return mid;
else if (!ans[0]) start=mid+1;
else end = mid-1;
}
return start;
}
int bSearch97(int start, int end, std::vector<int> sAns, std::vector<int> eAns, int maxVal) {
if (sAns[0]+sAns[1]==0) return start;
if (eAns[0]+eAns[1]==0) return end;
while(start + 1 < end && sAns[0]+sAns[1]!=maxVal) {
sAns = ask(++start);
if (sAns[0]+sAns[1]==0) return start;
}
while(start + 1 < end && eAns[0]+eAns[1]!=maxVal) {
eAns = ask(--end);
if (eAns[0]+eAns[1]==0) return end;
}
if(start+1==end || sAns[0]==eAns[0]) return -1;
int mid=(start+end+1)/2;
vector<int> midAns = ask(mid);
int result = bSearch97(start,mid,sAns,midAns,maxVal);
if (result != -1) return result;
return bSearch97(mid,end,midAns,eAns,maxVal);
}
int score97(int n) {
int m = min(500,n), maxVal=0;
vector<int> ans;
for(int i=0; i<m; i++) {
ans = ask(i);
int sum = ans[0]+ans[1];
if(sum==0) return i;
if (maxVal<sum) maxVal=sum;
}
return bSearch97(0,n-1,ask(0),ask(n-1),maxVal);
}
int bSearch(int start, int end, std::vector<int> sAns, std::vector<int> eAns) {
if (sAns[0]+sAns[1]==0) return start;
if (eAns[0]+eAns[1]==0) return end;
while(start + 1 < end && sAns[0]+sAns[1]!=eAns[0]+eAns[1]) {
if (sAns[0]+sAns[1] < eAns[0]+eAns[1]) {
sAns = ask(++start);
if (sAns[0]+sAns[1]==0) return start;
}
else {
eAns = ask(--end);
if (eAns[0]+eAns[1]==0) return end;
}
}
if(start+1==end || sAns[0]==eAns[0]) return -1;
int mid=(start+end+1)/2;
vector<int> midAns = ask(mid);
int result = bSearch(start,mid,sAns,midAns);
if (result != -1) return result;
return bSearch(mid,end,midAns,eAns);
}
int fulltask(int n) {
return bSearch(0,n-1,ask(0),ask(n-1));
}
int find_best(int n) {
return fulltask(n);
// return score97(n);
}
