import java.io.*;
import java.awt.*;
public class Problem2
{
    private static String primeNum (int num)
    {
	int ans;
	String result = "a prime number";
	for (int i = 2 ; i < num ; i++)
	{
	    ans = num / i;
	    if (num - (i * ans) == 0)
	    {
		result = "not a prime number";
		break;
	    }
	}
	return result;
    }


    public static void main (String[] args) throws IOException
    {
	BufferedReader in = new BufferedReader (new FileReader ("DATA2.txt"));
	PrintWriter out = new PrintWriter (new FileWriter ("OUT2.txt"));
	for (int y = 0 ; y < 5 ; y++)
	{
	    int line = Integer.parseInt (in.readLine ());
	    int p = 0;
	    int count = 0;
	    int pf = 0;
	    int count2 = 0;
	    int num = line + 1;
	    for (int i = line - 1 ; i >= 0 ; i--)
	    {
		//System.out.println (i);
		if (primeNum (i).equals ("a prime number"))
		{
		    //System.out.println (primeNum (i));
		    count++;
		    p = i;
		}
		if (count == 2)
		    break;
	    }
	    while (true)
	    {
		if (primeNum (num).equals ("a prime number"))
		{
		    count2++;
		    pf = num;
		}
		if (count2 == 2)
		    break;
		num++;
	    }
	    if (line - p > pf - line)
		out.println (pf);
	    else if (line - p < pf - line)
		out.println (p);
	    else
		out.println (pf);
	}
	out.close ();
    }
}