#include <fstream>
#include <iostream>
#include <string.h>

using namespace std;

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

int n, k, l ,a[101];
char c[100];

int main()
{
    f >> n;
    for ( int i = 1; i < 100; i++)
    {
        k = i;
        for ( int j = 1; j < i ; j++ )
        {
            k *= i;
            k %= 10;
        }
        a[i] = ( k + a[i-1] ) % 10;
    }

    while ( n > 0 )
    {
        f >> c;
        l = sizeof(c);
        if ( l >= 2 )
            g << a[(c[l - 2] - '0' ) * 10 + (c[l-1] - '0')] << '\n';
        else g << a[c[l - 1] - '0'] << '\n';
        n--;
    }
    g.close();
    f.close();

    return 0;
}