#include <iostream>
#include <string>
#include <vector>
#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long ll;
#define rep(i,n) for(int i=0;i<(n);i++)
const int INF = 1e9;

int main(void){
	int t; cin >> t;
	for (int i = 0; i < t; ++i){
		string s; cin >> s;
		int sum = 0;
		rep(i, s.size()){
			sum += s[i] - '0';
		}
		printf("%d\n", sum % 10);
	}
	return 0;
}