#include <bits/stdc++.h>
#define pb push_back
#define pf push_front
using namespace std;
#define F first
#define S second
typedef long long ll;
#define pii pair <int, int>
#define pll pair <ll, ll>
typedef long double ld;
const ll N = 2 * 1e5 + 10;
const ll mod = 1e9 + 7;
ll um(ll a, ll b){
return ((1LL * a * b) % mod + mod) % mod;
}
ll subr(ll a, ll b){
return ((1LL * a - b) % mod + mod) % mod;
}
ll binpow(ll x, ll step){
ll res = 1LL;
while(step){
if(step & 1) res = um(res, x);
x = um(x, x);
step /= 2;
}
return res;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
return 0;
}
