#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main()
{
    ifstream in ("cifra.in");
    short T;
    in >> T;
    string temp;
    int numE, sum;
    ofstream out ("cifra.out");
    for (int i = 0; i < T; i++)
    {
        sum = 0;
        in >> temp;
        if ((int)temp.length() - 2 >= 0)
            temp = temp.substr(temp.length() - 2);
        numE = atoi(temp.c_str());
        for (int j = 1; j <= numE; j++)
        {
            if (j % 4 == 0)
                sum += 6;
            else if (j % 4 == 1)
                sum += j;
            else if (j % 4 == 2)
                sum += (j * j) % 10;
            else
                sum += (((j * j) % 10) * j) % 10;
        }
        if (numE >= 10)
            out << (sum + 6 * (numE / 10)) % 10 << endl;
        else
            out << sum % 10 << endl;
    }
    in.close();
    out.close();
    return 0;
}