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

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

int t,l,sum;
char n[1005];
int rasp[]={0,1,5,2,8,3,9,2,8,7};

int main()
{
    int i;

    f>>t;
    for(i=1;i<=t;i++)
    {
        sum=0;
        f>>n;
        l=strlen(n)-1;
        if(l>=1) sum+=7*(n[l-1]-'0');
        sum+=rasp[n[l]-'0'];
        g<<sum%10<<"\n";
    }

    f.close();
    g.close();
    return 0;
}