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

using namespace std;

ifstream f("cifra.in");
ofstream g("cifra.out");

string s;

int a[] = {0, 1, 4, 7, 6, 5, 6, 3, 6, 9, 0};

void solve()
{
    f >> s;
    s = " " + s;
    int n = s.size() - 1, sum = 0;
    int x = (n > 1 ? ((s[n-1] - '0') * 10) : 0) + (s[n] - '0');
    for(int i = 1; i <= x; i ++){
        int y = i % 10;
        sum += a[y];
    }
    g << sum % 10 << '\n';
}

int main()
{
    int t, i;
    f >> t;
    for(i = 1; i <= t; i ++)
        solve();
    return 0;
}