#include<iostream>
#include <math.h>
#include <string>
using namespace std;

int main(){
	int n;
	int flag = 0;
	int t;
	cin >> n;
	for (int i1 = n - 100; i1 <= n + 100; i1++){
		for (int i2 = 2; i2 < i1; i2++){
			if (i1%i2 == 0){
				t = i1;
				flag = 1;
				break;
			}
			
		}
		if (flag == 1){
			break;
		}
	}
	cout << t << endl;
	return 0;
}