作业三（2）

#include<stdio.h>
int main(void)
{
    int n,m;
    double grade,total;

    n=0;
    m=0;
    total=0;
    printf("Enter grades:");
    scanf_s("%lf",&grade);

    while(grade>=0){
        total=total+grade;
        m++;
        if(grade<60)
            n++;
        scanf_s("%lf",&grade);
    }
    if(m!=0){
        printf("Grade average is %.2f\n",total/m);
        printf("Number of failuers is %d\n",n);
    }
    else
        printf("Grade average is 0\n");


    return 0;
}