int main()
{
int sub1,sub2,sub3,total;
printf("enter the marks in sub1,sub2,sub3");
scanf("%d%d%d", &sub1,&sub2,&sub3);
total=sub1+sub2+sub3;
printf("marks=%d",total);
if(total>100)
printf("grade A");
if((total<100)&&(total>75))
printf("grade B");
if((total<75)&&(total>50))
printf("grade C");
else
printf("grade D");
}