mixster

public class primes
{

    public static void main(String[] args)
    {
    final long startTime = System.nanoTime();

        boolean[] composite = new boolean[25000001];

    int limit = /*sqrt(25000000)*/ 5000;

        for(int i = 2; i <= limit; i++)
            if(!composite[i])

            {
        int o = i * 2 - 1;

              for(int j = i + o; j <= 25000000; j += o)
          composite[j] = true;

            }

    final long endTime = System.nanoTime();

    for(int i = 2; i <= 25/*000000*/; i += 1)
      if (!composite[i])
        System.out.println(2 * i - 1);

    System.out.print(endTime - startTime);
    System.out.println(" ns");
    }

}