#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define PII pair < int , int >
#define MOD 1000000007

using namespace std;

int n, m[100];
string s;

int digit(int n) {
    int x = 1;

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

    return x;
}

void solve(int n) {
    int x = 0;
    for (int j = 1; j <= n; j++)
         x += digit(j);

    m[n] = x % 10;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);

    ifstream cin("cifra.in");
    ofstream cout("cifra.out");

    for (int i = 1; i <= 99; i++) solve(i);

    cin >> n;
    while (n--) {
        cin >> s;

        reverse(s.begin(), s.end());

        int nr = s[0] - '0';
        if (s.size() > 1) nr += 10 * (s[1] - '0');

       cout << m[nr] << "\n";
    }
    return 0;
}