#include <fstream>

using namespace std;
ifstream cin("cifra.in");
ofstream cout("cifra.out");
int main()
{

    int T,zeci, unitati, sum;
    int uc_par[10] = {1,4,7,6,5,6,3,6,9,0}, uc_impar[10] = {1,6,3,6,5,6,7,4,9,0};
    char current_char;
    cin>>T;
    for (int i = 0 ;i < T; i++){
        unitati = 0;
        zeci = 0;
        sum = 0;
       cin.get(current_char);
       while(current_char < 48 || current_char > 57)
               cin.get(current_char);

       while(current_char >= 48 && current_char <= 57){
              zeci = unitati;
              unitati = current_char -'0';
              cin.get(current_char);
        }
        for(int j = 1; j<=unitati; j++){
            if(zeci%2 == 0){
                sum = sum + uc_par[j-1];
            } else {
                sum = sum + uc_impar[j-1];
            }
        }
        sum += zeci * 7;

        cout<<sum%10<<"\n";
    }
}