#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<stdlib.h>
#include<vector>
#include<string>
#include<sstream>
using namespace std;


int main(){

  int n;
  cin >> n;

  for(int i=n-100;i<=n+100;i++){
    for(int j=2;j<i;j++){
      if(i%j == 0){
        cout << i << endl;
        return 0;
      }
    }
  }

  return 0;
}