#include <algorithm>
#include <vector>
#include <cfloat>
#include <string>
#include <cmath>
#include <set>
#include <cstdlib>
#include <map>
#include <ctime>
#include <iomanip>
#include <functional>
#include <deque>
#include <iostream>
#include <cstring>
#include <queue>
#include <cstdio>
#include <stack>
#include <climits>
#include <sys/time.h>
#include <cctype>

using namespace std;

typedef long long ll;

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

}