Find out the Grade for student in C Programming

#include<stdio.h>
#include<conio.h>
void main()
{
int sum,ave,a,b,c,d,e;
clrscr();
printf("mark obtained in a,b,c,d,e");
scanf("%d %d %d %d %d",&a,&b,&c,&d,&e);
if(a<35 || b<35 || c<35 || d<35 || e<35)
{
printf("fail");
}
else
sum=a+b+c+d+e;
ave=sum/5;
printf("total mark=%d",sum);
printf("average=%d",ave);
if(ave>=60)
{
printf("first class");
}
else if(ave<=59 && sum>=50)
{
printf("second class");
}
else if(ave<=49 && ave>=40)
{
printf("third class");
}
else
{
printf("fail");
}
getch();
}