function factorial(n : double) : double;
begin
if n = 1
then factorial := 1
else factorial := n * factorial(n-1);
end;
var
i : integer;
n : integer;
s : double;
begin
s := 0;
write('n = '); readln(n);
for i:=1 to 2*N+1 do
s := s + factorial(i);
writeln('s = ',s:10:2);
end.