读优

#define getc() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)
char buf[1<<21],*p1=buf,*p2=buf;
char obuf[1<<24],*o=obuf;int wt[30];
struct IO_Tp
{

    bool is_digit(const char ch)
    {
        return '0' <= ch && ch <= '9';
    }
    
    IO_Tp& operator>>(int& res)
    {
        res = 0;
        char ch;
        bool neg(false);
        while (ch = getc(), !is_digit(ch))
            neg = ch == '-';
        do
            (res *= 10) += ch & 15;
        while (ch = getc(), is_digit(ch));
        neg ? res = -res : res;
        return *this;
    }
    
    IO_Tp& operator<<(int x){
        if(!x) {*o++='0';return *this;}
        if(x<0) *o++='-',x=-x;
        int l=0;
        while(x) wt[++l]=x%10,x/=10;
        while(l) *o++=wt[l--]+'0';
        return *this;
    }
    IO_Tp& operator<<(char ch)
    {
        *o++ = ch;
        return *this;
    }
    
} IO;

fwrite(obuf,o-obuf,1,stdout);