import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class e521{
    private static long tot=500000000000L;
    private static boolean[] Erast=new boolean[1000000];
    private static int[] primi=new int[78498];

    public static synchronized void add(int i){
        tot+=i;
    }
    public static void main(String[] args) throws InterruptedException{
        Tasker t1;
        Tasker t2;
        Tasker t3;
        Tasker t4;
        int y=0;
        int j;
        int multiple;
        for (j = 2; j<1000000; j++) {
            if (!Erast[j]) {
                primi[y++]=j;
                multiple = j * 2;
                while (multiple < 1000000) {
                    Erast[multiple] = true;
                    multiple += j;
                }
            }
        }
        System.out.println("Done Erast " + tot);
        ExecutorService exec=Executors.newFixedThreadPool(4);

        for(int i=3;i<10000000;i+=40000){
            t1=new Tasker(i);
            t2=new Tasker(i+10000);
            t3=new Tasker(i+20000);
            t4=new Tasker(i+30000);
            exec.execute(t1);
            exec.execute(t2);
            exec.execute(t3);
            exec.execute(t4);
            //System.out.printf("t da %d    >    ",i);

        }
        exec.shutdown();
        try{
            if(exec.awaitTermination(10, TimeUnit.SECONDS))
                System.out.println("Terminated");
            else System.out.println("TimeOut");
        }
        catch(InterruptedException e) {e.printStackTrace();}
        System.out.print(tot);
    }
    public static class Tasker implements Runnable{
        private final int value;
        private final int endValue;
        public Tasker(int i){
            value=i;
            endValue=value+(10000-2);
        }
        public void run(){
            boolean f=true;
            int n=value;
            for(n=value;n<=endValue;n+=2){
                f=true;
                int sqrtN=(int) Math.sqrt(n)+1;
                for(int i=0;primi[i]<sqrtN;i++){
                    if(n%primi[i]==0){
                        f=false;
                        add(primi[i]);
                        break;
                    }
                }
                if(f) add(n);
            }
            System.out.printf("   Terminated from %d to %d    %d\n",value,n, endValue);
        }
    }
}