头文件

#include<bits/stdc++.h>
#include<iostream>
#include<stdio.h>
#include<iomanip>
#include<stack>
#include<queue>
#include<algorithm>
#include<cstring>
#include<map>
#include<vector>
#include<numeric>
#include<iterator>
#include<cmath>
#define mem(a,x) memset(a,x,sizeof(a));
using namespace std;
int gcd(int a, int b) { return b == 0 ? a : gcd(b, a%b); }
int lcm(int a, int b) { return a * b / gcd(a, b); }
const int INF = 0x3f3f3f3f;
typedef long long ll;
typedef pair<int,int>Pi;
typedef pair<ll, ll>Pii;
map<int,int>mp;
map<int, char *>mp1;
map<char *, int>mp2;
map<char, int>mp3;
map<string,int>mp4;
map<char,int>mp5;
const int maxn = 200010;
const int mod=1000000007;
ll a[maxn];

int read(){
    int flag=1;
    int sum=0;
    char c=getchar();
    while(c<‘0‘||c>‘9‘){
        if(c==‘-‘)flag=-1;
        c=getchar();
    }
    while(c>=‘0‘&&c<=‘9‘){
        sum=sum*10+c-‘0‘;
        c=getchar();
    }
    return sum*flag;
}
ll Read(){
    int flag=1;
    ll sum=0;
    char c=getchar();
    while(c<‘0‘||c>‘9‘){
        if(c==‘-‘)flag=-1;
        c=getchar();
    }
    while(c>=‘0‘&&c<=‘9‘){
        sum=sum*10+c-‘0‘;
        c=getchar();
    }
    return sum*flag;
}
ll quickmul(ll a,ll b){
    ll ans=0;
    while(b){
        if(b&1){
            ans=(ans+a)%mod;
        }
        a=(a+a)%mod;
        b>>=1;
    }
    return ans;
}
ll quickpow(ll a,ll b){
    ll ans=1;
    while(b){
        if(b&1)
            ans=(ans*a)%mod;
        a=(a*a)%mod;
        b>>=1;
    }
    return ans;
}
int main()
{
    
    return 0;
}