C语言C++素数求和

#include <stdio.h>
#include <stdlib.h>
#include <math.h>


int main()
{
    int n,m=0,sum=0,a=0;
    scanf("%d", &n);
    for (int j = 2; j <= n; j++)
    {
        for (int i = 2; i <= sqrt(j); i++)
        {
            if (j%i == 0)
            {
                a++;
                break;
            }
        }
        if (a == 0)
        {
            sum += j;
            printf("%6d", j);
            m++;
            if (m % 5 == 0)
                printf("\n");
        }
        else
            a = 0;

    }
    printf("\ncount=%d,total=%d\n", m, sum);
    return 0;
}