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("input.in",'r')
# sys.stdout=open("outp.out",'w')
n=int(input())
c='C.'
if n%2==0:
	print(int(n*n/2))
	i=0
	while i < int(n/2):
		print(c*int(n/2))
		print(c[::-1]*int(n/2))
		i+=1
else:
	print(int((n*n)/2)+1)
	i=0 
	while i<int(n/2):
		print(c*int(n/2)+c[0])
		print(c[::-1]*int(n/2)+c[-1])
		i+=1
	print(c*int(n/2)+c[0])





# for i in range(n):
# 	for j in range(n):
# 		if c==True:
# 			print('C',end='')
# 			c=False
# 		else:
# 			print(".",end='')	
# 			c=True
# 	print()
# 	if i %2==0:
# 		c=False
# 	else:
# 		c=True

