write a program that accept marks in five subject and calculate percentage and respective grade

/*write a program that accept marks in five subject and calculate percentage and respective grade*/
#include<stdio.h>
main()
{
int a,b,c,d,e;
float per;
printf("enter marks in first subject:");
scanf("%d",&a);
printf("enter marks in 2nd subject:");
scanf("%d",&b);
printf("enter marks in 3rd subject:");
scanf("%d",&c);
printf("enter marks in 4th subject:");
scanf("%d",&d);
printf("enter marks in 5th subject:");
scanf("%d",&e);
per=(a+b+c+d+e)/(float)5;
printf("percentage=%f\n",per);
if(per<40)
{
printf("fail\n");
}
if(per<50)
{
printf("third\n");
}
if(per<60)
{
printf("second\n");
}
if(per<70)
{
printf("first\n");
}
}