#include <iostream>
using namespace std;

void parni(int unos, int niz[], int& rez, int& velicina)

{

	int k = 0;

	rez = 0;

	for (int i = 1; i < unos; i++)

	{

		if (i % 2 == 0)

		{

			rez += i;

			niz[k] = i;

			k++;

		}

	}

	velicina = k;

}

int main()

{

	int c, rj, velc;

	cin >> c;

	int *niz2 = new int[c/2 + 1];

	parni(c, niz2, rj, velc);

	cout << rj;

	cout << "\n";

	for (int i = 0; i < velc; i++)

	{

		cout << niz2[i] << ",";

	}
	system("pause");
	return 0;

}