#include <iostream>
#include <fstream>
using namespace std;
ifstream f("cifra.in");
ofstream g("cifra.out");
int s[10]={0,1,5,2,8,3,9,2,8,7},t,i,x,y;
char c,d;
int main()
{
    f>>t;
    for (i=1;i<=t;i++)
    {
        f>>d;
        c=NULL;
        while (f.peek()!='\n')
        {
            c=d;
            f>>d;
        }
        f.get();
        if (c)
        x=c-'0';
        else x=0;
        y=d-'0';
        g<<(x*7+s[y])%10<<endl;
    }
    return 0;
}