#include
int main()
{
int grade,counter=1,sum=0,e;
while(counter<=10)
{
printf("student grade\"%d\"=",counter);
scanf("%d",&grade);
if(grade<=100&&grade>=1)
{
sum+=grade;
counter++;
e=1;
}
else
{
e=0;
break;
}
}
if(e==1)
printf("class average=%f",sum/(float)(counter-1));
else
printf("enter real grade");
return 0;
}