#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int ec = 0;
int n;
int sift(int l, int r, int e, int le, int re) {
if(e <= 0) return -1;
int m = (l+r)/2;
int mr = m;
vector<int> mra;
for(mr = m; mr < r; ++mr) {
mra = ask(mr);
if(mra[0] + mra[1] == ec) {
break;
} else if(mra[0] + mra[1] == 0) {
return mr;
}
}
if(mr == r) {
return sift(l, m, e - (r - m), le, re + (r - m));
}
return max(sift(l, m, mra[0] - le - (mr - m), le, (mr - m) + mra[1]),
sift(mr+1, r, mra[1] - re, mra[0], re));
}
int find_best(int N) {
n = N;
srand(9399390);
for(int i = 0; i < min(n, 460); i++) {
int r = rand() % n;
vector<int> res = ask(r);
if(res[0] + res[1] == 0) return r;
ec = max(res[0] + res[1], ec);
//if(1ll*ec*ec*ec*ec > n) break;
}
return sift(0, n, ec, 0, 0);
}
