#include <stdio.h>

int ft_fibonacci(int index)
{
	if (index < 0)
		return -1;
	if (index == 0)
		return 0;
	if (index == 1)
		return 1;
	return ft_fibonacci(index - 2) + ft_fibonacci(index - 1);
}

Embed on website

To embed this program on your website, copy the following code and paste it into your website's HTML: