#include <stdio.h>
#include<math.h>
int main ()
{
float score;
int c;
scanf("%f",&score);
c=(int)score/10;
switch(c)
{
case 10: printf("成绩等级为A\n");break;
case 9: printf("成绩等级为A\n");break;
case 8: printf("成绩等级为B\n");break;
case 7: printf("成绩等级为C\n");break;
case 6: printf("成绩等级为D\n");break;
default: printf("成绩等级为E\n");
}
return 0;
}