#include <iostream>
using namespace std;

int main() {
    int n, m, a;
    string s;
    cin >> n;
    for (int _ = 0; _ < n; ++_) {
        cin >> s;
        m = s.size();
        for (int i = 1; i < m; ++i) {
            for (int j = 0; j < m - i; ++j) {
                a = s[j] + s[j + 1] - 96;
                s[j] = a % 10 + a / 10 + 48;
            }
        }
        cout << s[0] << endl;
    }
    return 0;
}