#include <bits/stdc++.h>
using namespace std;

int t;

char buf[100002];

vector<int> v;

int main(){
	cin >> t;
	while (t--){
		scanf("%s", buf);
		v.clear();
		int siz = strlen(buf);
		for (int i = 0; i < siz; i++){
			v.push_back(buf[i] - '0');
		}
		while (v.size()>1){
			vector<int> tmp;
			for (int i = 0; i + 1 < v.size(); i++){
				int F = v[i] + v[i + 1];
				if (F >= 10){
					F %= 10;
					F++;
				}
				tmp.push_back(F);
			}
			v = tmp;
			tmp.clear();
		}
		printf("%d\n", v[0]);
	}
	return 0;
}