int main()

{

    int s;

    int n;

    float avg;

    scanf("%d,%d",&s,&n);   //特别注意的地方

   // scanf("%d",&n);

    avg=s/n;

    printf("avg is %f \n",avg);

    return ;

}

#include <stdio.h>

int main()

{

    int i;

    int n=;

    int s=;

    while()

    {

        scanf("%d",&i);

        if(i==)

        {

           break;

        }

        n++;

        s+=i;

    }

    printf("%d,%d\n",s,n);

    return ;

}

./input.out | ./avg.out