#include <iostream>
#include <string>
#include <vector>
using namespace std;

int main()
{
	int t; cin >> t;
	for (int i = 0; i < t; i++) {
		string S; cin >> S;
		vector<int>num;
		for (int j = 0; j < S.size(); j++) {
			num.push_back(S[j] - '0');
		}
		while (num.size() != 1) {
			vector<int>tmpS;
			for (int k = 1; k < num.size(); k++) {
				int a = num[k] + num[k - 1];
				if(a<10) tmpS.push_back(a);
				else tmpS.push_back(a % 10 + 1);
			}
			num = tmpS;
		}
		cout << num[0] << endl;
	}

    return 0;
}