#include<iostream>
#include<string>
#include<string.h>
#include<algorithm>
#include<stdio.h>
#include<cmath>
#include<vector>
#include<utility>
#include<stack>
#include<queue>
#include<list>
#include<bitset>
#include<functional>

#define FOR(i, a, b) for(int i=(a);i<=(b);i++)
#define RFOR(i, a, b) for(int i=(a);i>=(b);i--)
#define MOD 1000000007
#define INF 1000000000
#define PI 3.14159265358979

using namespace std;
typedef pair<int, int> P;

int main(void) {
	int n;
	bool flag = true;

	cin >> n;

	FOR(i, n - 100, n + 100) {
		FOR(t, 2, i-1) {
			if (i%t == 0) {
				cout << i << endl;
				flag = false;
				break;
			}
		}
		if (flag == false) {
			break;
		}
	}

	return 0;
}