while True:
try:
s,t=eval(input("請輸入身高,請輸入體重："))#檢驗數據是否存在異常
BMI=t/pow(s,2)
break
except NameError:#如果數據不是整數的話則報錯
continue
print("BMI數值為:{:.2f}".format(BMI))
if BMI<18.5:
who,dom="偏瘦","偏瘦"
elif 18.5<=BMI<=23.9:
who,dom="正常","正常"
elif 24<=BMI<=24.9:
who,dom="正常","偏胖"
elif 25<=BMI<=27.9:
who,dom="偏胖","偏胖"
elif 28<=BMI<=29.9:
who,dom="偏胖","肥胖"
else:
who,dom="肥胖","肥胖"
print("BMI指標為:國際{},國內{}".format(who,dom))