#include
int main()
{
float score;
char c;
printf("score=");
do
{
scanf("%f",&score);
if(score100)
printf("Input error,Please input again(0~100):");
}while(score100);
switch((int)(score/10))
{
case 10:
case 9:c='A';break;
case 8:c='B';break;
case 7:c='C';break;
case 6:c='D';break;
default:c='E';
}
printf("%cn",c);
return 0;
}