如题

inline int read()
{
	int s=0,w=1;
    char ch=getchar();
    while(ch<'0' || ch>'9'){
        if(ch=='-') w=-1;
        ch=getchar();
    }
    while(ch>='0' && ch<='9'){
        s=(s<<3)+(s<<1)+(ch^48);//精华
        ch=getchar();
    }
    return s*w;
}