#include <fstream>
#include <cstring>

using namespace std;

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

int t, lg, i, j, a, b, v[] = {0, 1, 5, 2, 8, 3, 9, 2, 8, 7}, cif;
char n[200];

int main() {
    fin >> t;

    for(i = 1;i <= t;i++) {
        fin.get();
        fin.get(n, 200);

        lg = strlen(n);
        if(lg == 1) a = 0;
        else a = n[lg - 2] - '0';
        b = n[lg - 1] - '0';

        cif = (v[a] * 7 + v[b]) % 10;

        fout << cif << '\n';
    }

    fin.close();
    fout.close();

    return 0;
}