//多测不清空，十年OI一场空
#include<bits/stdc++.h>
#include<algorithm>
#include<queue>
#include<cstring>
#include<string>
int read();
int readc();
int read()
{
	int x=0,f=0;char ch=getchar();
	while(!isdigit(ch)){f|=ch=='-';ch=getchar();}
	while(isdigit(ch)){x=(x<<3)+(x<<1)+(ch^48);ch=getchar();}
	return x;
}
int readc()
{
	char ch=getchar();
	while((ch==' ')||(ch=='\n')||(ch=='\r')) ch=getchar();
	return ch;
}

