#include <bits/stdc++.h>
using namespace std;

int main(void) {
	int i, j, k;
	int n;
	cin >> n;
	for (int j = n - 100; j <= n + 100; ++j) {
		if(j==1||j==2||j==3)continue;
		for (int i = 2; i <= sqrt(j); ++i) {
			if(j%i==0){
						cout<<j<<endl;
						return 0;
			}
		}

	}
	return 0;
}