#include <bits/stdc++.h>
#define PI 3.14159265359
#define NIL -1
using namespace std;
const int64_t MOD = 1e9 + 7;

int main() {
	int N;
	cin >> N;

	int ans = 0;
	for (int i = N - 100; i < N + 101; i++) {
		//cout << "i:" << i << endl;

		for (int j = 2; j <= sqrt(i); j++) {
			//cout << "j:" << j << endl;

			if (i % j == 0) {
				cout << i << endl;
				return 0;
			}
		}
	}
}