#include<iostream>
#include <algorithm>
int x[10000000];
using namespace std;
int main()
{
	int N;
	cin >> N;
	for (int i = 1; i <= N; i++)
	{
		x[i] = 1;
	}
	for (int j = 2; j <= N; j++)
	{
		for (int i = 1; i <= N; i++)
		{
			if (i % j == 0)
			{
				x[i] = 0;
			}
		}
	}
	for (int i = 1; i <= N; i++)
	{
		if (x[i] == 1)
		{
			cout << i;
		}
	}
	return 0;
}