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).
import math

n = int(input())
print(math.ceil(n*n/2))
odd_s = ''
even_s = ''
for i in range(1, n+1):
    odd_s += ('C' if i%2 == 1 else '.')
    even_s += ('C' if i%2 == 0 else '.')
for i in range(1, n+1):
    if i%2 == 1:
        print(odd_s)
    else:
        print(even_s)
