算法题-素数求和

#include <stdio.h>
#include <math.h>
#define MAX 1000
int main(void){
    int i,j,n,m,sum,a[MAX],flag;
    scanf("%d",&n);
    while(n--){
        sum = 0;
        scanf("%d",&m);
        for(i=0;i<m;i++){
            scanf("%d",&a[i]);
        }
        for(i=0;i<m;i++){
            if(a[i]==1){
                continue;
            } 
            flag = 0;
            for(j=2;j<=sqrt(a[i]);j++){
                if(a[i]%j==0){
                    flag = 1;
                    break;
                }
            }
            if(flag==0){
                sum+=a[i];
            }
        }
        printf("%d\n",sum);
    }
    printf("\n");
    return 0;
}