program cifra;
var f,g:Text;
    i,t,j,jj,x,s,p:longint;
begin
assign(f,'cifra.in');
assign(g,'cifra.out');
reset(f);
rewrite(g);
read(f,t);
for i:=1 to t do
  begin
  read(f,x);
  s:=0;
  for j:=1 to x do
    begin
    p:=1;
    for jj:=1 to j do
      p:=p*(j mod 10);
    s:=s+p;
    end;
  writeln(g,s mod 10);
  end;
close(f);
close(g);
end.