int student
10, i=0, a=0, b=0, c=0, d=0, f=0;
do{
cin >> student
i;
switch(student
i/10){
case 9 :
case 8 :
b++;
break;
case 7 :
c++;
break;
case 6 :
d++;
break;
default :
if(student
i!=999)
f++;
break;
}
i++;
}while((student
i-1 != 999) && (i<10));
cout <<"A :" <