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%2 == 0):
  print(n*n//2)
  row1 = ('.C' * (n//2))
  row2 = ('C.' * (n//2))
  res  = (row1+'\n'+row2+'\n') * (n//2)
  print(res)
else:
  print(n*(n//2+1) - n//2)
  row1 = ('.C' * (n//2)) + ('.')
  row2 = ('C.' * (n//2)) + ('C')
  res  = (row1+'\n'+row2+'\n') * (n//2) + row1
  print(res)
