#include <stdio.h>

 #include <stdlib.h>

 int main()

 {

     int socre;

     printf("plz input a score:");

     scanf("%d",&socre);

     //printf("socre:%d",socre);

     if (socre >  || socre < )

     {

         printf("plz input socre between 0 and 100");

         return -;

     }

     socre /= ;

     switch(socre)

     {

     case :

     case :

         printf("A");

         break;

     case :

         printf("B");

         break;

     case :

          printf("C");

          break;

     case :

        printf("D");

        break;

      default:

         printf("E");

     }

     return ;

 }