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")
n=int(input())
print((n*n+1)//2)
for i in range(n):
	# for j in range(n):
	# 	if (i+j)%2==0:
	# 		print("".join("C"),end="")
	# 	else:
	# 		print("".join("."))
	print("".join(("C" if (i+j)%2==0 else "." )for j in range(n)))
