#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;
string s;

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

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

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

    return x % 10;
}
 
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
 
    ifstream cin("cifra.in");
    ofstream cout("cifra.out");

    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 << solve(nr) << "\n";
    }
    return 0;
}