def _walk(node: int, side: int, save=False):
    if (node < totcolcnt):
        if save:
            return_list.append(node)
        return None
    else:
        node = int((node - totcolcnt))
        child = int(tree[node][side])
        return child
def _walk(node: int, side: int, save=False):
    if (node < totcolcnt):
        if save:
            return_list.append(node)
        return None
    else:
        node = int((node - totcolcnt))
        child = int(tree[node][side])
        return child