def METHOD_NAME(fan_intake_num, fan_exhaust_num, psu_intake_num, psu_exhaust_num):
    airflow_debug("fan_intake_num: %d, fan_exhaust_num: %d, psu_intake_num: %d, psu_exhaust_num: %d" %
                  (fan_intake_num, fan_exhaust_num, psu_intake_num, psu_exhaust_num))
    if fan_intake_num == 0 and fan_exhaust_num == 0 and psu_intake_num == 0 and psu_exhaust_num == 0:
        airflow_error("get all fans and psus air flow failed")
        return "N/A"
    if fan_intake_num > fan_exhaust_num:
        airflow_debug("fan intake number %d more than fan exhaust number %s, set board air flow: intake")
        return "intake"
    if fan_intake_num < fan_exhaust_num:
        airflow_debug("fan intake number less than fan exhaust number, set board air flow: exhaust")
        return "exhaust"
    airflow_debug("fan intake number equal to exhaust number, check psu air flow")
    if psu_intake_num > psu_exhaust_num:
        airflow_debug("psu intake number more than psu exhaust number, set board air flow: intake")
        return "intake"
    if psu_intake_num < psu_exhaust_num:
        airflow_debug("psu intake number less than psu exhaust number, set board air flow: exhaust")
        return "exhaust"
    airflow_debug("fan and psu intake and exhaust number equal, return intake")
    return "intake"