def bmi_recommendation(bmi):
    """Given a BMI, return a pair
    (bool - True if BMI is healthy) and (str - recommendation)
    """
    if bmi < 18.5:
        return (False, 'You are underweight. You should see a doctor.')
    elif bmi < 25:
        return (True, 'You are within the ideal weight range.')
    return (False, 'You are overweight. You should see a doctor.')