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).
# Danny Garcia
# 5/8/2019

from math import ceil

x = int(input())

print(ceil(x * x / 2))

for row in range(x):
	
	rowCurrent = ""

	for column in range(x):
		if (row % 2 == 0 and column % 2 == 0) or (row % 2 == 1 and column % 2 == 1):
			rowCurrent += "C"
		else:
			rowCurrent += "."

	print(rowCurrent)