const uc:array[0..19]of byte=(0,1,5,2,8,3,9,2,8,7,7,8,4,7,3,8,4,1,5,4);
var   f,fo:text;
      s:string;
      n,l,a,b:integer;
      t:word;
      i,suma:longint;

begin
  assign(f,'cifra.in');reset(f);
  assign(fo,'cifra.out');rewrite(fo);

  read(f,t);

  for i := 1 to t do
  begin
    read(f,s);
    l:=length(s);
    n:= (ord(s[l-1])-$30)*10 + (ord(S[l])-$30);
    a:= n div 20;
    b:= n mod 20;
    suma:= (a *4 + uc[b])mod 10;
    writeln(fo,suma);
  end;


  close(f);
  close(fo);
end.