快读板子fread

 struct ios {

     inline char read(){

         static const int IN_LEN=<<|;

         static char buf[IN_LEN],*s,*t;

         return (s==t)&&(t=(s=buf)+fread(buf,,IN_LEN,stdin)),s==t?-:*s++;

     }

     template <typename _Tp> inline ios & operator >> (_Tp&x){

         static char c11,boo;

         for(c11=read(),boo=;!isdigit(c11);c11=read()){

             if(c11==-)return *this;

             boo|=c11=='-';

         }

         for(x=;isdigit(c11);c11=read())x=x*+(c11^'');

         boo&&(x=-x);

         return *this;

     }

 } io;

 int main(){io>>a>>b;}