#include<bits/stdc++.h>
using namespace std;
template<typename T> void qr(T& x){
	x=0; char c=getchar(); int f=1;
	for(; !isdigit(c); c=getchar()) if(c=='-') f=-1;
	for(; isdigit(c); c=getchar()) x=x*10+(c-'0');
	x*=f;
}
template<typename T> void qw(T x){
	if(x<0) putchar('-'), x=-x;
	if(x>10) qw(x/10);
	putchar(x%10+'0');
}
int main(){
	//freopen(".in", "r", stdin);
	//freopen(".out", "w", stdout);
	
	return 0;
}
