#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
typedef pair <int, int> PII;
constexpr int NMAX = 2e5 + 5;
set <int> S[NMAX];
int ans;
int CntStanga[NMAX];
void DivideConquer (int Left, int Right) {
if (Left > Right) return;
int mid = (Left + Right) / 2;
vector <int> a = ask(mid);
int tip = a[0] + a[1];
CntStanga[mid] = a[0];
if (tip == 0) {
ans = mid;
return;
}
auto it = S[tip].insert(mid).first;
if (it == S[tip].begin())
DivideConquer(Left, mid-1);
else if (CntStanga[*prev(it)] != CntStanga[mid]) DivideConquer(Left, mid-1);
if (ans != -1) return;
if (it == prev(S[tip].end()))
DivideConquer(mid + 1, Right);
else if (CntStanga[*next(it)] != CntStanga[mid]) DivideConquer(mid+1, Right);
}
int find_best(int n) {
ans = -1;
DivideConquer(0, n-1);
return ans;
}
