//#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 subtask0(int n) {
std::vector<int> ans;
for(int i=0; i<n; i++) {
ans = ask(i);
if(ans[0]+ans[1]==0) return 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 bSearch(int start, int end, std::vector<int> sAns, std::vector<int> eAns, int maxVal) {
// printf("start=%d, end=%d, ",start,end);
int result = -1;
if (eAns[0]==sAns[0]) return -1;
int mid = (start+end+1)/2;
// printf("mid=%d ",mid);
vector<int> mAns = ask(mid);
if (mAns[0]+mAns[1]==0) return mid;
int midL=mid, midR=mid;
if(mAns[0]+mAns[1]<maxVal) {
midL = start;
for(int i=mid-1; i>start; i--) {
mAns = ask(i);
if(mAns[0]+mAns[1]==0) return i;
if(mAns[0]+mAns[1]==maxVal) {midL=i; break;}
}
midR = end;
for(int i=mid+1; i<end; i++) {
mAns = ask(i);
if(mAns[0]+mAns[1]==0) return i;
if(mAns[0]+mAns[1]==maxVal) {midR=i; break;}
}
}
// printf("midL=%d, midR=%d\n",midL,midR);
if (start<midL) result = bSearch(start,midL,sAns,mAns,maxVal);
if (result != -1) return result;
if(midR<end) return bSearch(midR,end,mAns,eAns,maxVal);
return -1;
}
int find_best(int n) {
// if (n<=5000) {return subtask0(n);}
vector<int> sAns = ask(0) ; if (sAns[0]+sAns[1]==0) return 0;
vector<int> eAns = ask(n-1); if (eAns[0]+eAns[1]==0) return n-1;
int m = min(450,n), maxVal=0, maxIdx=-1;
for(int i=0; i<m; i++) {
vector<int> ans = ask(i);
if (maxVal<ans[0]+ans[1]) {maxVal=ans[0]+ans[1]; maxIdx=i;}
}
// printf("maxVal:%d, maxIdx:%d\n",maxVal,maxIdx);
return bSearch(0,n-1,sAns,eAns,maxVal);
}
