#include <bits/stdc++.h>
#include <cmath>
using namespace std;

ifstream fin("cifra.in");
ofstream fout("cifra.out");

int suma(int n) {
    int rez = 1;
    for(int i = 1; i <= n; i++)
        rez = (rez * (n % 10)) % 10;
    return rez % 10;
}

int main() {
    int n, s;
    int t;
    fin >> t;
    for(int i = 1; i <= t; i++) {
        int s = 0;
        fin >> n;
        for(int i = 1; i <= n; i++) {
            s = s + suma(i);
        }
        fout << s % 10 << '\n';
    }
}