#include<iostream>
#include<cstdlib>
#include<string>
using namespace std;
int main(){
    string s,tmp;
    int num,n;
    cin >> n;
    while(n--){
        cin >> s;
        while(s.size()!=1){
            tmp.clear();
            for(int i=0;i<s.size()-1;i++){
                num = int(s[i]-'0')+int(s[i+1]-'0');
                if(num>=10) num-=9;
                tmp=tmp+to_string(num);
            }
            s = tmp;
            //cout << s << endl;
        }
        cout << s << endl;
    }
    return 0;
}