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())
# print((n//2)*n)
l,l1=[],[]
if n%2!=0:
	print(1+((n//2)*n)+n//2)
	l.append('C.'*(n//2))
	l.append('C')
	l1.append('.C'*(n//2))
	l1.append('.')
	for i in range(n):
		if i%2==0:
			print(*l,sep='')
		else:
			print(*l1,sep='')
else:
	print((n//2)*n)
	l.append('C.'*(n//2))
	l1.append('.C'*(n//2))

	for i in range(n):
		if i%2==0:
			print(*l,sep='')
		else:
			print(*l1,sep='')
