s = input()
k = 0
s = list(s)
for i in s:
	if i == 'a':
		i = 'b'
		k = k + 1
	elif i == 'b':
		i = 'a'
		k = k + 1
	elif i == 'B':
		i = 'A'
		k = k + 1
	elif i == 'A':
		i = 'B'
		k = k + 1
s1 = ''
for i in s:
	s1 = s1 + i
print(s1, '\n', k)