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

using namespace std;
ifstream fin ("cifra.in");
ofstream fout ("cifra.out");
string s;

int main()
{
    int n, cnt = 0, num, nr, c, sum = 0;
    fin >> n;
    for (int k = 0; k < n; ++k) {
    cnt = 0;
    fin >> s;
    if (s.size() > 1)
        num = (s[s.size() - 2] - 48) * 10 + (s[s.size() - 1] - 48);
    else
        num = s[0] - 48;

        for (int i = 1; i <= num; ++i) {
        nr = 1;
        c = i % 10;
        for (int j = 0; j < i; ++j) {
            nr *= c;
            nr %= 10;
        }
        sum += nr;
        sum %= 10;
    }
    fout << sum % 10 << "\n";
    }
    return 0;
}