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())
board_size=n*n

def attack_check(board):
  for  row_index in range(n):
    for col_index in range(n):
      if board[row_index][col_index]==1:
        if row_index-1>=0:
          if  board[row_index-1][col_index]==1:
            return False
        if col_index-1>=0:
          if board[row_index][col_index-1]==1:
            return False
  return True

def solve_util(board,total_coders_placed):
  if total_coders_placed == board_size:
    return attack_check(board)
  row_index = total_coders_placed//n 
  col_index = total_coders_placed%n
  for i in range(2):
    board[row_index][col_index]= i 
    if solve_util(board,total_coders_placed+1):
      return True 
    board[row_index][col_index]=0
  return False

def solve():
  board= [[0]*n for i in range(n)]
  if solve_util(board, 0):
    print(board_size)
    for row in board:
      for cell in row:
        if cell ==1:
          print('C', end = ' ')
        else:
          print('.', end=' ')
      print()
solve()