#include <iostream>
#include <fstream>
#include <cstring>
using namespace std;
ifstream f ("cifra.in");
ofstream g ("cifra.out");
unsigned t,e,i,j,x,v[11];
char sir[1000000000];
void cifr ()
{
    unsigned i,j;
    for (i=1;i<10;i++)
    {
        x=1;
        for (j=1;j<=i;j++) x=x*i;
        v[i]=(x)%10;
    }
}

int cif (unsigned x)
{
    unsigned i,q=0;
    for (i=1;i<=x;i++)
    {
        q=(q+v[i%10])%10;

    }
    return q;
}

int main()
{
    f>>t;
    cifr();
    for (e=1;e<=t;e++)
    {
        f>>sir;
        x=(sir[strlen(sir)-2]-48)*10+(sir[strlen(sir)-1]-48);;
        g<<cif(x)<<'\n';
    }
    return 0;
}