import java.util.ArrayList;

public class Main
{
  /**
   * The sum of the primes below 10 is 2 + 3 + 5 + 7 = 17
   * Find the sum of all the primes below two million.
   * @param args
   */
  public static void main(String[] args)
  {
    ArrayList<Integer> primes = new ArrayList<Integer>();
    int upper = 2000000;
    primes.ensureCapacity(upper);
    for (int i = 0; i < upper; i++)
    {
      primes.add(i);
    }
    long sum = 0;
    for (int i = 2; i <= upper / i; i++)
    {
      if ( primes.get(i) > 0 )
      {
        for (int k = i*i; k < upper ; k+=i)
        {
          primes.set(k,0);
        }
      }
    }
    for (int i = 2; i < upper; i++)
    {
      sum += primes.get(i);
    }
    System.out.println(sum);
  }
}