#include <algorithm>
#include <cstdio>
#include <iostream>
#include <map>
#include <cmath>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <stdlib.h>
#include <stdio.h>
#include <bitset>
using namespace std;
#define FOR(I,A,B) for(int I = (A); I < (B); ++I)
typedef long long ll;

int main(){
  int N;
  cin >> N;
  FOR (i, max(4, N - 100), N + 101) {
    FOR (j, 2, i) {
      if(i % j == 0) {
        cout << i << endl;
        return 0;
      }
    }
  }
  return 0;
}