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 :
	c = 'C.'*(n//2)
	h = '.C'*(n//2)
	print((n**2)//2)
	for i in range(n//2):
		print(c)
		print(h)
else:
	c = 'C.'*(n//2)+'C'
	h = '.C'*(n//2)+'.'
	print((n**2+1)//2)
	for i in range(n//2):
		print(c)
		print(h)
	print(c)
