#include <fstream>

using namespace std;

ifstream in("cifra.in");
ofstream out("cifra.out");

int rez(int x)
{
    int v[10]={0, 1, 5, 2, 8, 3, 9, 2, 8, 7};
    int i, S=0, k, y;

    if (x<=9)
   return v[x];

    else

    {
        k=x/9;
        S=7*k;
        S=S%10;
        k=x%9;
        y=x/10;
        S=S+v[k-y];
    }

    return S%10;
}

int main ()
{
    int n, i, x;
    in>>n;
    for (i=1; i<=n; i++)
    {
        in>>x;
        out<<rez(x)<<endl;
    }
    return 0;
}