EWU Grade Calculation

#include<stdio.h>
int main()
{
    int n,count1,count2,count3,count4,count5,count6,count7,count8,count9,count10,count11,count12, total, total1;
    count1 = 0;
    count2 = 0;
    count3 = 0;
    count4 = 0;
    count5 = 0;
    count6 = 0;
    count7 = 0;
    count8 = 0;
    count9 = 0;
    count10 = 0;
    count11= 0;
    count12 = 0;
    while(n != -1)
    {
        printf("Enter your number: ");
        scanf("%d",&n);
        if(n>=97){
            printf("A+\n");
            count1 = count1+1;

        }
        else if(n>=90 && n<97){
            printf("A\n");
            count2 = count2+1;
        }
        else if(n>=87 && n<90){
            printf("A-\n");
            count3=count3+1;
        }
        else if(n>=83 && n<87){
            printf("B+\n");
            count4 = count4+1;
        }
        else if(n>=80 && n<83){
            printf("B\n");
            count5 = count5+1;
        }
        else if(n>=77 && n<80){
            printf("B-\n");
            count6 = count6+1;
        }
        else if(n>=73 && n<77){
            printf("C+\n");
            count7= count7+1;
        }
        else if(n>=70 && n<73){
            printf("C\n");
            count8 = count8+1;
        }
        else if(n>=67 && n<70){
            printf("C-\n");
            count9 = count9+1;
        }
        else if(n>=63 && n<67){
            printf("D+\n");
            count10 = count10 +1;
        }
        else if(n>=60 && n<63){
            printf("D\n");
            count11 = count11+1;
        }
        else if(n<60 && n!=-1){
            printf("F\n");
            count12 = count12+1;
        }
        else
            break;

    }

    printf("No Of A+'s %d\n",count1);
    printf("No Of A's %d\n",count2);
    printf("No Of A-'s %d\n",count3);
    printf("No Of B+'s %d\n",count4);
    printf("No Of B's %d\n",count5);
    printf("No Of B-'s %d\n",count6);
    printf("No Of C+'s %d\n",count7);
    printf("No Of C's %d\n",count8);
    printf("No Of C-'s %d\n",count9);
    printf("No Of D+'s %d\n",count10);
    printf("No Of D's %d\n",count11);
    printf("No Of F's %d\n",count12);

    total = count1+count2+count3+count4+count5+count6+count7+count8+count9+count10+count11;
    printf("Total Number of Passed Students: %d\n",total);
    printf("Total Number of Failed Students: %d\n",count12);





}