// 
//

#include <iostream> 
#include <vector> 
#include <cstdlib>

using namespace std;


vector<long> getPrimes( long nmax )
{
  vector<long> primeRef ;
  primeRef.push_back(2);
  primeRef.push_back(3);

  for ( long p = 5; p < nmax; p+=2 ) {
    int index = 0;
    long t = primeRef[index]; // take only primes to test
    while  (t*t <= p) {  // and only those smaller sqrt(p) 
      if ( p % t == 0 ) { // not prime, give up
	break;
      }
      index ++;
      t = primeRef[index];
    }

    if (t*t > p ) { // found prime
      primeRef.push_back(p); // append to list
    }
  }

  return primeRef;

}


int main() 
{
  vector<long> primes  =  getPrimes( 1000000 );

  cout << "N-Primes found : " << primes.size() << endl;

 
  return 0;

}