import java.util.*;
import java.lang.*;
import java.io.*;
public class Main
 {
     static boolean isPrime(int n)  
      {
        if (n <= 1) return false;  
        if (n <= 3) return true;  
        if (n % 2 == 0 || n % 3 == 0) return false;  
        for (int i = 5; i * i <= n; i = i + 6)  
            if (n % i == 0 || n % (i + 2) == 0)  
            return false;  
          
        return true;}  
    
    static int nextPrime(int N)  
      {  
        if (N <= 1)  
            return 2;  
        int prime = N-1;  
        boolean found = false;  
        while (!found)  
        {  
            prime++;  
      
            if (isPrime(prime))  
                found = true;  
        }  
      
        return prime;  
    }  
	public static void main (String[] args)
	 {
	 Scanner s=new Scanner(System.in);
	 int a=s.nextInt();
	 System.out.println(nextPrime(a));}}
	 
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz