#include <fstream>
#include <cstring>
using namespace std;

int z[100];

int putere(int x)
{
    int rez=1,i;
    for (i=1;i<=x;i++)
    {
        rez=rez*x;
        rez=rez%10;
    }
    return rez;
}

int main()
{
    ifstream f("cifra.in");
    ofstream g("cifra.out");
    char v[101];
    int d;
    for (d=1;d<=100;d++)
        z[d]=(z[d-1]+putere(d))%10;
    f>>d;
    f.get();
    while (d--)
    {
        f.getline(v,101);
        int l=strlen(v);
        if (l==1) g<<z[v[0]-'0']<<'\n';
        else g<<z[(v[l-2]-'0')*10+(v[l-1]-'0')]<<'\n';
    }
    return 0;
}