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).
def ii():
  return int(input())
def ss():
  return [x for x in input()]
def si():
  return [int(x) for x in input().split()]
def mi():
  return map(int, input().split())

a = ii()
s = 0
if a % 2 == 0:
  print(a * a // 2)
else:
  print((a // 2) * (a // 2) + (a // 2 + 1) * (a // 2 + 1))
for i in range(a):
  if a % 2 == 0:
    s = (s + 1) % 2
  for i in range(a):
    if s:
      print(".", end="")
    else:
      print("C", end="")
    s = (s + 1) % 2
  print()