var f,g:text;
    n,s,t,i,k:longint;
function putere(x:integer):byte;
var i,z:longint;
begin
  z:=x;
  for i:=2 to x do
     z:=x*z;
  z:=z mod 10;
  putere:=z;
end;
begin
  assign(f,'cifra.in');
  reset(f);
  assign(g,'cifra.out');
  rewrite(g);
  readln(f,t);
  for k:=1 to t do
  begin
    read(f,n);
    s:=0;
    for i:=1 to n do
    begin
      s:=(s+putere(i))mod 10;
    end;
    writeln(g,s);
  end;
  close(f);
  close(g);
end.