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).
a=int(input())
if a%2==1:
	print((a//2)**2+((a-a//2)*(a//2+1)))
else:
	print(a*a//2)
if a%2==0:
	for i in range(a):
		if i%2==0:
			print('C.'*(a//2))
		else:
			print('.C'*(a//2))
elif a%2==1:	
	for i in range(a):	
		if i%2==0:
			print('C.'*((a-1)//2),end='')
			print('C')
		else:
			print('.C'*((a-1)//2),end='')
			print('.')
