#include <stdio.h>
int main () {
char level;
float score;
scanf("%f",&score);
switch( iZ (score/10))
{ 
case 10:
case9:level='A';break;
case8:level='B';break;
case7:level='C';break;
case6:level='D';break;
default:level='E';
}
printf("考试成绩等级为:%c\n",level); 
}