import sys

data = input()

if len(data) < 1 or len(data) > 100:
	sys.exit()

list = list(data)

for i in range(0,len(data)):

	j = list[i]

	if j.islower():
		list[i] = j.upper()

	elif j.isupper():
		list[i] = j.lower()

print(''.join(list))