{ problema cifra - infoarena.ro}

program cifra_infoarena;
type sir=array[1..3000] of longint;

var n:longint;
    f,g:text;
    c,cif,ult:byte;
    a:sir;
    i,t:longint;

procedure citire(var a:sir);
begin
    assign(f,'cifra.in');  reset(f);
    readln(f,t);
  for i:=1 to t do readln(f,a[i]);
close(f);
end;

procedure cifra(n:longint);
var p:longint;
    k,i1:longint;
begin
    ult:=0;
  for i1:=1 to n do begin
     c:=i1 mod 10;
   if c=1 then cif:=1
          else
      if c=2 then
         case i1 mod 4 of
           0:cif:=6;
           1:cif:=2;
           2:cif:=4;
           3:cif:=8;
                 end
           else
   if c=3 then
       case i1 mod 4 of
          0:cif:=1;
          1:cif:=3;
          2:cif:=9;
          3:cif:=7;
            end
         else
  if c=4 then
       case i1 mod 2 of
          0:cif:=6;
          1:cif:=4;
            end
          else
  if c=5 then cif:=5
        else
  if c=6 then cif:=6
        else
  if c=7 then
      case i1 mod 4 of
         0:cif:=7;
         1:cif:=9;
         2:cif:=3;
         3:cif:=1;
          end
       else
  if c=8 then
        case i1 mod 4 of
         0:cif:=8;
         1:cif:=4;
         2:cif:=2;
         3:cif:=6;
           end
        else
   if c=9 then
        case i1 mod 2 of
          0:cif:=1;
          1:cif:=9;
           end;

   ult:=(ult+cif)mod 10;
       end;

end;


begin
  citire(a);

 assign(g,'cifra.out');  rewrite(g);
 for i:=1 to t do begin
 if a[i]<maxlongint then begin
 cifra(a[i]);
 writeln(g,ult);
                         end;
      end;
  close(g);
end.