const a:array[0..9,0..3] of byte=((0,0,0,0),(1,1,1,1),(6,2,4,8),(1,3,9,7),(6,4,6,4),
      (5,5,5,5),(6,6,6,6),(1,7,9,3),(6,8,4,2),(1,9,1,9));
var s,s1:string;
    p,i,nr,c,n,t:integer;
    f,g:text;

function ucif(k:integer):integer;
var s,i:integer;
begin
  s:=0;
  for i:=1 to k do
    begin
      inc(s,a[i mod 10,i mod 4]);
    end;
  ucif:=s mod 10;
end;

begin
  assign(f,'cifra.in');
  reset(f);
  assign(g,'cifra.out');
  rewrite(g);
  readln(f,t);
  for i:=1 to t do
    begin
      readln(f,s);
      p:=length(s)-1;
      if p<1 then p:=1;
      s1:=copy(s,p,2);
      val(s1,n,c);
      writeln(g,(4*(n div 20)+ucif(n mod 20)) mod 10);
    end;
  close(f);
  close(g);
end.