def get_ovulation_day(cycle: dict) -> int:
    """
    Get the ovulation day of a cycle.
    :param cycle: cycle dict
    :return: ovulation day
    """
    try:
        is_biphasic = "classification_results" in cycle and cycle["classification_results"][0]["results"][
            "predicted_class"] == "biphasic"
        if not is_biphasic:
            return None

        has_ov_detection = "ov_detection_results" in cycle
        if not has_ov_detection:
            return None

        ov_detection_results = cycle["ov_detection_results"][0]["results"]["ovulation_day"]
        return ov_detection_results
    except Exception as e:
        # print(e)
        return None