program fact:
var m,n,fact,sum:integer;
begin
   n := read;
   fact := 1;
   while 1 <= n do
   begin
      m := n;
      sum := 0;
      while 1 <= m do
      begin
	  sum := sum + fact;
	  m := m + -1
      end;
      fact := sum;
      n := n + -1
   end;
   output(fact)
end fact.
