#include<fstream>
#include<cmath>
using namespace std;

int T, lastDigit, preLastDigit;
string N;
int sum[2][10] = {0, 1, 5, 2, 8, 3, 9, 2, 8, 7, 0, 1, 7, 0, 6, 1, 7, 4, 8, 7};

int main()
{
    ifstream fin("cifra.in");
    ofstream fout("cifra.out");
    fin>>T;
    for(;T > 0; --T) {
        fin>>N;
        lastDigit = *(N.end() - 1) - '0';
        preLastDigit = N.length() > 1 ? *(N.end() - 2) - '0' : 0;
        fout<<(((preLastDigit * 7) %10 + sum[preLastDigit%2][lastDigit])%10)<<"\n";
    }
    return 0;
}