#include <iostream>
#include <cstdio>
using namespace std;
short int v[]={0,1,5,2,8,3,9,2,8,9};
int main()
{
    freopen("cifra.in","r",stdin);
    freopen("cifra.out","w",stdout);
    int t,i;
    char c,d,e;
    scanf("%d",&t);
    for(i=1;i<=t;i++)
    {
      c=getchar();
      d=getchar();
      if(d<'0' || d>'9')
        cout<<v[c-'0']<<endl;
      else{
        e=getchar();
        while(e>='0' && e<='9')
        {
          c=d;
          d=e;
          e=getchar();
        }
        cout<<(v[d-'0']+7*(c-'0'))%10<<endl;
      }
    }
    return 0;
}