关于快读

#define bs (1<<20)
char buf[bs], *p1, *p2;
#define gc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,bs,stdin),p1==p2)?EOF:*p1++)
template<typename T>
inline void read(T& x){
	x = 0; int w = 1;
	char ch = gc();
	while(ch < '0' || ch > '9'){
		if(ch == '-') w = -w;
		ch = gc();
	}
	while(ch >= '0' && ch <= '9')
		x = (x<<3)+(x<<1)+(ch^48), ch = gc();
	x *= w;
}
template<typename T, typename ...Args>
inline void read(T& x, Args& ...y){
	return read(x), read(y...);
}