#include<bits/stdc++.h>
using namespace std;
``
bool zhishu(int n)
{
	if (n < 2) return 0;
	for (int i = 2; i * i <= n; ++i)
	{
		if (n % i == 0) 
			return 0;
	}
	return 1;
}
int main()
{
	long long n,cnt=0,sum=2;
	cin >> n;
	if (n < 2)
	{
		cout << '0' << endl;
		return 0;
	}
	else if (n == 2)
	{
		cout << "2" << endl;
		cout << "1" << endl;
		return 0;
	}
	for (int i = 2; sum <= n; i++)
	{
		if (zhishu(i))
		{
			cout << i << endl;
			cnt++;
			sum += i;
		}
	}
	cout << cnt;
	return 0;
}