#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <map>
#include <set>
#include <cstdio>
#include <cmath>
#define rep(i,l,n) for(lint i=l;i<n;i++)
#define rer(i,l,n) for(lint i=l;i<=n;i++)
#define all(a) a.begin(),a.end()
#define o(a) cout<<a<<endl
#define pb(a) push_back(a)
#define mk(a,b) make_pair(a,b)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef vector<int> vi;
typedef vector<lint> vli;
typedef vector<vi> vvi;
typedef pair<int,int> pii;

bool is_prime(int n){
	for(int i=2;i*i<=n;i++){
		if(n%i==0) return false;
	}
	return n!=1;
}

int main(){
	int n;
	cin>>n;
	rep(i,n-100,n+101){
		if(is_prime(i)==0 && i!=1){
			o(i);
			break;
		}
	}
}