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 os
n = int(input())
s=''
if n%2==0:
	print((n*n)//2)
else:
	print((n*n)//2+1)
for i in range(1,n+1):
	for j in range(1,n+1):
		if i%2==0:
			if j%2==0:
				s+='C'
			else:
				s+='.'
		else:
			if j%2==0:
				s+='.'
			else:
				s+='C'
	s+='\n'
print(s)