#include
int main()
{
int grade;
scanf("%d",&grade);
printf("your grade:");
switch((int)grade/10)
{
case 10:
case 9:printf("A\n");break;
case 8:printf("B\n");break;
case 7:printf("C\n");break;
case 6:printf("D\n");break;
default:printf("E\n");break;
}
return 0;
}