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).
# import sys
# sys.stdin = open("test.in","r")
# sys.stdout = open("test.out","w")
n=int(input())
if n%2==0:
	print(int((n*n)/2))
	for i in range(n):
		for j in range(n-1):
			if i%2==0 and j%2==0:
				print('C',end="")
			elif i%2==0 and j%2==1:
				print('.',end="")
			elif i%2==1 and j%2==0:
				print('.',end="")
			else:
				print('C',end="")
		if i%2==0:
			print('.')
		else:
			print('C')				
else:
	a=int(n/2)
	print(((a+1)**2)+a**2)
	for i in range(n):
		for j in range(n-1):
			if i%2==0 and j%2==0:
				print('C',end="")
			elif i%2==0 and j%2==1:
				print('.',end="")
			elif i%2==1 and j%2==0:
				print('.',end="")
			else:
				print('C',end="")	
		if i%2==0:
			print('C')
		else:
			print('.')			
				