Iahub likes chess very much. He even invented a new chess piece named Coder. A Coder can move (and attack) one square horizontally or vertically. More precisely, if the Coder is located at position (*x*, *y*), he can move to (or attack) positions (*x* + 1, *y*), (*x*–1, *y*), (*x*, *y* + 1) and (*x*, *y*–1).

Iahub wants to know how many Coders can be placed on an *n* × *n* chessboard, so that no Coder attacks any other Coder.
The first line contains an integer *n* (1 ≤ *n* ≤ 1000).
n = int(input())
if n%2 == 0:
	res = (n*(n//2))
else:
	res = (n*(n//2) + (n//2) + 1)
print (res)
line1 = []
line2 = []
turn = True
for i in range(n):
	if turn: 
		line1.append('C')
		line2.append('.')
	else:
		line1.append('.')
		line2.append('C')
	turn = not turn
turn = True
str1 = "".join(line1)
str2 = "".join(line2)
for i in range(n):
	if turn:
		print (str1)
	else:
		print (str2)
	turn = not turn