include <bits/stdc++.h>

using namespace std; // #define int long long

define push_b push_back

define push_f push_front

define pop_f pop_front

define pop_b pop_back

define sec second

define fir first

const int inf = 1e9 + 7;

signed main() {

ios::sync_with_stdio(0);
cout.tie(0);
cin.tie(0);

}