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

int main(){
	int t,x;
	string s;
	cin >> t;
	
	while(t--){
		cin >> s;
		while(s.size()>1){
			string s2;
			for(int i=0;i<s.size()-1;i++){
				x=(s[i]-'0')+(s[i+1]-'0');
				if(x>=10) x-=9;
				s2+=x+'0';
			}
			s=s2;
		}
		cout << s << endl;
	}
	return 0;
}