#include <stdio.h>

#define MAX 1000

int checkSNT(int n);
int main()
{
    int n, i, flag;
    int a[MAX];
    printf ("nhap so phan tu mang n= ");
    scanf("%d", &n );

    for (i=0; i<n; i++)
    {

      printf("[%d] ", i );
      scanf("%d", &a[i] );
    }
    int count = 0;

    

    for(i=2; i<n; ++i)
    {
        // flag = 1 -> SNT
        flag = checkSNT(i);

        if(flag == 1)
           count++;
    }

    printf("So cac so nguyen to la %d",count );
}



int checkSNT(int n)
{
    int j, flag = 1; 

    for(j=2; j <= n/2; ++j)
    {
        if (n%j == 0)
        {
            flag =0;
            break;
        }
    }
    return flag;
}