#include <bits/stdc++.h>

using namespace std;

/*
1  1 1
2  4 6
3  7 3
4  6 6
5  5 5
6  6 6
7  3 7
8  6 4
9  9 9
0  0 0
*/

int main()
{
    ios_base:: sync_with_stdio(0);
    cin.tie(0);

    freopen("cifra.in", "r", stdin);
    freopen("cifra.out", "w", stdout);

    string s;
    cin >> s;

    int lastDigit[] = {0, 1, 5, 2, 8, 3, 9, 2, 8, 7, 7,  8, 4, 7, 3, 8, 4, 1, 5, 4, 4};

    int ans;
    if(s.size() <= 1)
    {
        cout << lastDigit[s[0] - '0'];
        return 0;
    }

    int nr = (s[s.size() - 2] - '0')* 10 + (s[s.size() - 1] - '0');
    int cat = nr / 20;
    int rest = nr % 20;
    cout << (cat * 4 + lastDigit[rest]) % 10;
    return 0;
}