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())
a='C.'
if n%2==0:
	print(int(n*n/2))
	for i in range(n):
		if i%2==0:
			print(a*int(n/2))
		else:
			k=a[::-1]
			print(k*int(n/2))
else:
	print(int(n*n/2)+1)
	for i in range(n):
		if i%2==0:
			print(a*int(n/2)+a[0])
		else:
			k=a[::-1]
			print(k*int(n/2)+k[0])