var     t,i,j:longint;
        n:string;
        u:byte;
        f,f2:text;
        a:array[0..9,1..4] of integer;

procedure init;
var     i,j:integer;
begin
  for i:=0 to 9 do
  a[i,1]:=i;
  for i:=0 to 9 do
  for j:=2 to 4 do
  a[i,j]:=a[i,j-1]*i mod 10;
end;

procedure ultimacifra(n:string);
var     i,j:longint;
        c:integer;
        k:int64;
begin
  val(n,k,c);
  u:=0;
  for i:=1 to k do
  begin
    j:=i mod 4;
    if j=0 then j:=4;
    u:=(u+a[i mod 10,j]) mod 10;
  end;
  writeln(f2,u);
end;

begin
  init;
  assign(f,'cifra.in');
  reset(f);
  readln(f,t);
  assign(f2,'cifra.out');
  rewrite(f2);

  for i:=1 to t do
    begin
      readln(f,n);
      ultimacifra(n);
    end;
  close(f2);
  close(f);
end.