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).
n = int(input())

if n == 1:
  print("1\nC")
  exit(0)

even = "C." * (n // 2) + ("C" if n & 1 else "")
odd = ".C" * (n // 2) + ("." if n & 1 else "")

print(n * n // 2 + (n & 1))
for row in range(n):
  print(odd if row & 1 else even)