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).
from math import floor, ceil

n = int(input())
if n % 2 != 0:
    a = ceil(n / 2)
    b = floor(n / 2)
    k = a * ((n // 2) + 1) + b * (n // 2)
    print(k)
    l = 0
    for i in range(1, n + 1):
        for j in range(1, n + 1):
            if l == 0:
                if j % 2 != 0:
                    print('C', end="")
                else:
                    print('.', end="")
            else:
                if j % 2 == 0:
                    print('C', end="")
                else:
                    print('.', end="")
        if l == 0:
            l = 1
        else:
            l = 0
        print()
else:
    k = n * (n // 2)
    l=0
    print(k)
    for i in range(1, n + 1):
        for j in range(1, n + 1):
            if l == 0:
                if j % 2 != 0:
                    print('C', end="")
                else:
                    print('.', end="")
            else:
                if j % 2 == 0:
                    print('C', end="")
                else:
                    print('.', end="")
        if l == 0:
            l = 1
        else:
            l = 0
        print()



