快读

inline int read(){
    int x=0,f=1;
    char ch=getchar();
    while(ch<'0'||ch>'9'){
        if(ch=='-')
            f=-1;
        ch=getchar();
    }
    while(ch>='0'&&ch<='9'){
        x=(x<<1)+(x<<3)+(ch^48);
        ch=getchar();
    }
    return x*f;
}
#define gc (p1==p2&&(p2=(p1=fr)+fread(fr,1,1<<21,stdin))==p1?EOF:*p1++)
char ch,fr[1<<21],*p1=fr,*p2=fr;
bool fig;
void rd(int&x)
{
    while(!isdigit(ch=gc)&&ch^45); if(fig=ch==45)ch=gc;
    x=ch-48;
    while( isdigit(ch=gc)) x=ch-48+x*10;
    if(fig) x=-x;
}

快写

inline void write(int x)
{
    char F[200];
    int tmp=x>0?x:-x ;
    if(x<0)putchar('-') ;
    int cnt=0 ;
       while(tmp>0)
       {
           F[cnt++]=tmp%10+'0';
           tmp/=10;
       }
       while(cnt>0)putchar(F[--cnt]) ;
}