#include <fstream>
#include <cstring>
using namespace std;
ifstream f ("cifra.in");
ofstream g ("cifra.out");
int n,i,t,sum,v[]={0,1,5,2,8,3,9,2,8,7,7},l;
char p[105];
int main()
{
    f>>n;
    for(i=1;i<=n;++i)
    {
        f.get () ;
        f.get(p,101) ;
        l=strlen(p);
        sum=(v[p[l-2]-'0']*7+v[p[l-1]-'0'])%10;
        g<<sum<<"\n";
    }
    return 0;
}