program fibonacci_rek;

var n  :  longint;
   
function fib( n : longint) : longint;
begin
   if n = 0 then
	  fib := 0
   else
	  if n = 1 then
		 fib := 1
	  else
		 fib := fib(n-1) + fib(n-2)
end; { fib }

begin
   write('n='); readln(n);
   write('fib(',n,')='); writeln(fib(n):5);
end.