許浩浩

1. a=input()
   
2. b=input()
   
3. if(len(a)>3 and len(b)<=20)and(len(b)>3 and len(b)<=20):
   
4.     print(len(a))
   
5.     print(len(b))
   
6.     n=a+b
   
7.     for i in range(len(n)-1,-1,-1):
   
8.         print(n[i],end="")
   
9. else:
   
10.     print("error")

複製代碼