#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main() {
    int K;
    cin>>K;
    for(int i=0;i<K;i++){
        string s;
        cin>>s;
        if(s.size()==1) {cout<<s<<endl;continue;}
        while(1){
            string c;
            for(int j=0;j<s.size()-1;j++) {
                int x = s[j] - '0' + s[j+1] - '0';
                if ( x > 9 ) c = c + to_string(1+x%10);
                else c = c + to_string(x);
            }
            if(c.size() == 1 ) {cout<<c<<endl;break;}
            s = c;
        }
    }
    return 0;
}