weight = float(input('请输入你的体重(千克)')) height = float(input('请输入你的身高(米)')) bmi = weight / (height * height) if bmi < 18.5: print('体重过轻') else: if bmi < 23.9: print('正常') else: if bmi < 27.9: print('超重') else: print('肥胖')