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).
# -*- coding: utf-8 -*-
"""
Created on Wed Jun 16 20:42:52 2021

@author: nagan
"""

n = int(input())
if n % 2 == 0:
    print(int((n * n)/2))
    for i in range(n):
        if i % 2 == 0:
            print("C." * (n // 2))
        else:
            print(".C" * (n // 2))
else:
    print(((n * n)//2) + 1)
    for i in range(n):
        if i % 2 == 0:
            print("C." * (n // 2) + "C")
        else:
            print(".C" * (n // 2) + ".")