#include<iostream>
#include<sstream>
#include<algorithm>
#include<map>
#include<set>
#include<queue>
#include<complex>
#include<cstdio>
#include<cstdlib>
#include<cstring>
// #define DEBUG

using namespace std;

// typedef pair<int,int>P;
// typedef complex<double>P;

typedef long long int ll;
typedef unsigned long long int ull;

const int INF = 1e9;
const double EPS=1e-9;

bool isPrime(int num){
  if(num <= 1)return true;
  for(int i = 2 ; i*i <= num ; i++){
    if(num % i == 0)return false;
  }
  return true;
}

int main(int argc, char *argv[])
{
  int N;
  cin >> N;
  for(int i = N-100  ; i <= N+100  ; i++){
    if(!isPrime(i)){
      cout << i << endl;
      break;
    }
  }
  return 0;
}