#include <fstream>

using namespace std;
ifstream in("cifra.in");
ofstream out("cifra.out");
int ultim(int n)
{
    int p=1, c=n%10;
    for (int i=0; i<n; i++)
    {
        p=(p*c)%10;
    }
    return p;
}
int suma(int n)
{
    int s;
    for (int i=1; i<n; i++)
    {
        s+=ultim(i);
        s%=10;
    }
    return s;
}
int main()
{
    int n, t, l;
    string s;
    in >> t;
    for (int i=0; i<t; i++)
    {
        in >> s;
        l=s.length();
        if (l==1)
        {
            n=s[0]-'0';
        }
        else
        {
            n=(s[l-2]-'0')*10+(s[l-1]-'0');
        }
        out << (n/20*4+suma(n%20))%10 << "\n";
    }
    in.close();
    out.close();
    return 0;
}