#include
void fun(int n)
{
switch(n/10)
{
case 1:
case 2:
case 3:
case 4:
case 5:printf("成绩不及格\n");break;
case 6:printf("成绩为D等\n");break;
case 7:printf("成绩为C等\n");break;
case 8:printf("成绩为B等\n");break;
case 9:
case 10:printf("成绩为A等\n");break;
}
}
void main()
{
int n;
scanf("%d",&n);
fun(n);
}