题解 | #单词倒排#

num=input()

# 1.遍历字符串。如果是小写字母或者大写字母，str1加进去。否则加" "
str1=" "
for i in num:
    if  (i>='a' and i<='z') or (i>='A' and i<='Z'):
        str1=str1+i
    else:
        str1=str1+" "

# 2.按照" "分割成list的元素
list2=str1.split(" ")

# 3.list倒序
list2=list2[::-1]

# 4.遍历list，输出元素，并且以" "结尾
for i in list2:
    print(i,end=" ")