백준 2475

#include <iostream>
#include <string>
#include <vector>
using namespace std;


int main(void)
{
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	int nums = 0;

	for (int i = 0; i < 5; ++i)
	{
		int num;
		cin >> num;

		nums += (num * num);
	}

	cout << nums % 10;
	return 0;
}