题解 | #单词倒排#

import re

x = list(str(input()))

y = []
for i in x:
    if re.search(r'[^a-zA-Z]+', i) is not None:
        y.append(' ')
    else:
        y.append(i)

y = ''.join(y).split(' ')
y = list(reversed(y))
y = ' '.join(y)
print(y)