#include<stdio.h>

int main()
{
   printf("It is a program about grading\n");
   float num_of_fail=0;
   float a=0,total_grade=0,avg_grade=0;
   float per_of_fail=0,per_of_pass=0;
   int n,i;
   printf("\n No. of course: n= ");
   scanf("%d",&n);

   for(i=1;i<=n;++i)
   {
       printf("Enter grade#%d:",i);
       scanf("%f",&a);
       if(a>=80&&a<=100)
            printf("\nyour grade is=A+\n");
       else if(a>=75&&a<80)
            printf("\nyour grade is=A\n");
       else if(a>=70&&a<75)
            printf("\nyour grade is=A-\n");
       else if(a>=65&&a<70)
            printf("\nyour grade is=B+\n");
       else if(a>=60&&a<65)
            printf("\nyour grade is=B-\n");
       else if(a>=50&&a<60)
            printf("\nyour grade is=c\n");
       else if(a>=40&&a<50)
            printf("\nyour grade is=D\n");
       else if(a>100||a<0)
            printf("Invalid intput");
       else
            printf("\n fail\n");
       total_grade+=a;

       if(a<40.0)
        num_of_fail++;
   }
    avg_grade=total_grade/n;
   printf("Average grade=%f\n",avg_grade);
   printf("Number of fail=%f\n",num_of_fail);
    per_of_fail=(num_of_fail/n)*100;
   printf("Percentage of fail= %f\n",per_of_fail);
   printf("Number of pass=%f\n",n-num_of_fail);
   per_of_pass=(1-(per_of_fail)/100)*100;
   printf("Percentage of pass= %f\n",per_of_pass);

   return 0;

}