// Cifra.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <fstream>
#include <cmath>
using namespace std;
int n,s,x;
int main()
{
	ifstream fin("cifra.in");
	ofstream fout("cifra.out");
	fin >> n;
	for (int  i = 1; i <= n; i++)
	{
		x = pow(i, i);
		s += x;
		
	}
	fout << s%10;
	
	
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file