import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.PrintStream;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Yukicoder solver = new Yukicoder();
        solver.solve(1, in, out);
        out.close();
    }

    static class Yukicoder {
        private boolean isPrime(int n) {
            for (int i = 2; i < n; i++) {
                if (n % i == 0) return false;
            }
            return true;
        }

        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int num = in.nextInt();

            for (int i = num - 100; i < num + 100; i++) {
                if (!isPrime(i)) {
                    System.out.println(i);
                    return;
                }
            }
        }
    }
}