import java.io.*;
import java.util.*;

public class lego {

    static List<Integer> ns = new ArrayList<>();
    static Writer writer = null;
    static Scanner in;
    static long lst;
    static long start;
    static int cpl;


    static Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));


    public static boolean alive = true;

    public static void main(String[] args) {

        try {
            in = new Scanner(System.in);
            writer = new BufferedWriter(new FileWriter(new File("primes.txt")));
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(1);
        }



        Thread controll = new Thread(new Runnable() {
            @Override
            public void run() {
                while (true) {
                    System.out.print("Enter \"stop\" to stop the loop");
                    String c = in.nextLine();
                    if (c.equalsIgnoreCase("stop")) {
                        alive = false;
                    }
                }
            }
        });

        int i = 1;
        controll.start();
        lst = java.time.Instant.now().getEpochSecond();
        start = java.time.Instant.now().getEpochSecond() - 1;
        while (alive) {
            boolean isPrime = true;
            for (int x=2; x<i; x++) {
                int w = i%x;
                //System.out.println(i + "%" + x + "=" + w);
                if (w==0) {
                    isPrime = false;
                }
            }

            if (isPrime) {
                try {
                    writer.write("" + i + "\n");
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            i++;
            cpl++;

            if (i%100 == 0) {
                long seconds = java.time.Instant.now().getEpochSecond();
                System.out.println("\n " + i + " calculations completed!");
                long cps = cpl / (seconds - start);
                lst = seconds;
                //cpl = 0;
                System.out.println("Speed: " + cps + " calculations per second");
            }
        }

        //writer.write((i+3) + ": " + x + "\n");
        try {writer.close();} catch (Exception ex) {/*ignore*/}
        controll.stop();
    }
}