#include <stdio.h>

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

int main() 
{
    int a = ft_fibonacci(0);
    printf("%d", a);
    
    return 0;
}