def calculate_bmi(weight, height):
    """计算BMI指数"""
    if height <= 0:
        raise ValueError("身高必须是正数")
    if weight < 0:
        raise ValueError("体重不能为负数")
    return weight / (height ** 2)

def get_bmi_category(bmi):
    """根据BMI指数返回对应的健康类别"""
    if bmi < 18.5:
        return "偏瘦"
    elif 18.5 <= bmi < 24:
        return "正常"
    elif 24 <= bmi < 28:
        return "过重"
    elif 28 <= bmi < 30:
        return "轻度肥胖"
    elif 30 <= bmi < 35:
        return "中度肥胖"
    else:
        return "重度肥胖"

def main():
    try:
        # 获取用户输入
        weight = float(input("请输入您的体重(kg):30 "))
        height = float(input("请输入您的身高(m): 138"))
        
        # 计算BMI
        bmi = calculate_bmi(weight, height)
        
        # 获取健康类别
        category = get_bmi_category(bmi)
        
        # 输出结果
        print(f"\n您的BMI指数为: {bmi:.2f}")
        print(f"健康类别: {category}")
        
    except ValueError as e:
        print(f"输入错误: {e}")
    except Exception as e:
        print(f"发生错误: {e}")

if __name__ == "__main__":
    main()