var  j,t,n,x,s:word;
     a:longint;
     f,g:text;
begin
assign(f,'cifra.in');
reset(f);
assign(g,'cifra.out');
rewrite(g);
readln(f,n);
while not eof(f) do
 begin
 s:=0;
 readln(f,x);
 for j:=1 to x do
  begin
  a:=1;
  for t:=1 to j do
   begin
   a:=a*j;
   a:=a mod 10;
   end;
  s:=s+a;
  end;
 writeln(g,s mod 10);
 end;
 close(f);
 close(g);
 end.