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).
# usr/bin/python
#import naoqi
import math
from sys import stdin, stdout
#f = open('in.in')

def main():
    n = int(stdin.readline())
    p = True
    print(math.ceil(n*n/2))
  #arr = [int(x) for x in stdin.readline()
    for i in range(0, n):
      for j in range(0, n):
        if p == True:
          if j%2 == 0:
            print("C", end="")
          else:
            print(".", end="")
        else:
          if j%2 == 1:
            print("C", end="")
          else:
            print(".", end="")
      print("\n")
      if p == True:
        p = False
        continue
      if p == False:
        p = True
        continue




main()