#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define ff first
#define ss second
#define pb push_back
#define SZ(x) ((int)(x).size())
#define all(x) x.begin(), x.end()
#define debug(x) cout << #x << ": " << x << " "
#define nl cout << "\n"
#define rep(i, a, b) for(int i = (a); i < (b); i++)
#define per(i, a, b) for(int i = (a); i >= (b); i--)
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
vector<int> ask(int i);
int cerca(int x, int ql, int qr){
assert(ql <= qr);
int l = ql, r = qr + 1;
while(r - l > 1){
int m = (l + r) / 2;
vector<int> res = ask(m);
res[0] -= x;
if(res[0] < 0){
l = m; break;
} else if(res[0] == 0) l = m;
else r = m;
}
vector<int> res = ask(l);
if(res[0] == 0 && res[1] == 0){
return l;
}
return cerca(res[0], l + 1, qr);
}
int find_best(int N){
return cerca(0, 0, N - 1);
}
