#include <iostream>
#include <fstream>
#include <sstream>
using namespace std;
const short num[10][4]={{0, 0, 0, 0}, {1, 1, 1, 1}, {6, 2, 4, 8}, {1, 3, 9, 7}, {6, 4, 6, 4}, {5, 5, 5, 5}, {6, 6, 6, 6}, {1, 7, 9, 3}, {6, 8, 4, 2}, {1, 9, 1, 9}};
main()
{
    ifstream f1("test.in");
    ofstream f2("test.out");
    string n;
    int sum[100]={0}, i, t, k;
    //Make an array with results
    for (i = 1; i < 100; i++){
        sum[i] = (num[i%10][i%4] + sum[i-1]) % 10;
    }
    f1 >> t;
    for (i = 0; i <= t; i++)
    {
        stringstream buf;
        getline(f1,n);
        if (n.length() == 1)
        {
            buf << n;
            buf >> k;
            f2 << sum[k] << "\n";
        }
        if (n.length() > 1)
        {
            string var;
            var = var + n[n.length()-2] + n[n.length()-1];
            buf << var;
            buf >> k;
            f2 << sum[k] << "\n";
        }
    }
}