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())
a = [[0] * n for i in range(n)]

k=0
for i in range(n):
  for j in range(n):
    a[i][j] = '.'
for i in range(n):
  for j in range(n):
    if (i % 2 == 1) and (j % 2 == 1):
      a[i][j]='C'
      k += 1
    if (i % 2 == 0) and (j % 2 == 0):
      a[i][j]='C'
      k += 1
print(k)
for i in range(n):
  for j in range(n):
     print(a[i][j], end=' ')
  print()