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).
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# (c) MidAndFeed aka ASilentVoice
# ===============================
import math, fractions
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n = int(input())
s = "C."*(pow(n,2))
if n%2==0:
	print(n*(n//2))
else:
	print((n*(n+1)//2) - n//2)
for i in range(n):
	if i%2==0:
		print(s[:n])
	else:
		print(s[1:n+1])