#include <iostream>
using namespace std;

int main() {
  int n;
  cin >> n;
  for (int i = n - 100; i < n + 101; ++i) {
    for (int j = 2; j < i; ++j) {
      if (i % j == 0) {
        cout << i << endl;
        return 0;
      }
    }
  }
  return 0;
}