fread

#include<cstdio>
#include<cctype>
#define rg register 
using namespace std;
#define gc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
static char buf[1<<21],*p1=buf,*p2=buf;
inline int read(){
	rg int f=0,x=0;
	rg char ch=gc();
	while(!isdigit(ch))	f|=(ch=='-'),ch=gc();
	while(isdigit(ch))	x=(x<<1)+(x<<3)+(ch^48),ch=gc();
	return f?-x:x;
}