#include <fstream>
#include <bitset>
#define N 500000
using namespace std;
ifstream fin ("eratostene1.in");
ofstream fout ("eratostene1.out");
int n,i,x,j;
int ct=0;
bool prim;
int main()
{
    fin>>n;
    while(n--)
    {
        fin>>x;
        if(x%2==1)
        {
            prim=1;
            if(x<=1)prim=0;
            else if(x<=3)prim=1;
            else if(x%2==0 || x%3==0) prim=0;
            else
                for(i=5;i*i<=x && prim; i+=6)
                  if(x%i==0 || x%(i+2)==0)prim=0;
            if(prim==1) ct++;
        }
        else if(x==2) ct++;
    }
    fout<<ct;
    return 0;
}