#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin
#include <ios>			//fixed
#include <iomanip>		//setprecision
#include <sstream>		//stringstream

using namespace std;

inline bool JudgePrimeNumber(const long long int a) {
	//素数か判定する

	if (a < 2) { return false; }
	if (a == 2) { return true; }
	if (a % 2 == 0) { return false; }

	for (long long int i = 3; i <= a / i; i += 2) {
		if (a % i == 0) {
			return false;
		}
	}
	return true;
}

inline bool JudgeMultipleOfThree(const long long int n) {
	//3の倍数か判定する

	long long int temp = n;
	long long int sum = 0;
	while (temp > 0) {
		sum += temp % 10;
		temp /= 10;
	}
	if (sum % 3 == 0) { return true; }
	else { return false; }
}

inline bool JudgeCompositeNumber(const long long int a) {
	//合成数か判定する

	if (a < 4) { return false; }
	if (a % 2 == 0) { return true; }
	if (a < 10) {
		if (a == 9) { return true; }
		else { return false; }
	}
	else {
		if (a % 10 == 5) { return true; }
		if (JudgeMultipleOfThree(a)) { return true; }
		if (!JudgePrimeNumber(a)) { return true; }
	}
	return false;
}

int main() {

	int N;
	cin >> N;

	for (int i = N - 100; i <= N + 100; i++) {
		if (JudgeCompositeNumber(i)) {
			cout << i << endl;
			return 0;
		}
	}

	return 0;

}