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).
rows = int(input())
import math
print(math.ceil(rows**2/2))

odd = ''.join('C' if not c % 2 else '.' for c in range(rows))
even = ''.join('C' if c % 2 else '.' for c in range(rows))

for r in range(rows):
    print(even) if r % 2 else print(odd)