```int fib(int n)
{
	if (n == 1)
		return 1;
	if (n == 2)
		return 2;
	else
		return fib(n - 1) + fib(n - 2);
}
int main()
{
	int n = 0;
	while (~scanf("%d",&n) )
	{
		printf("%d", fib(n));
	}
	return 0;
}