常用头文件
#include<iostream>
#include<cstdio>
#include<string>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<set>
#include<map>
#define INF 0x3f3f3f3f
#define LL long long
using namespace std;
#define IOS std::ios::sync_with_stdio(false);std::cin.tie(0);
const int N =100 ;
signed main(){
IOS
}