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())
answer = ""
answer2 = ""
if n % 2 == 0:
    answer = answer + str(int((n ** 2) / 2)) + "\n"
else:
    answer = answer + str(int((n ** 2) / 2) + 1) + "\n"
for i in range(0, n):
    answer2 = ""
    for j in range(0, n):
        if i % 2 == 0:
            if j % 2 == 0:
                answer2 = answer2 + "C"
            else:
                answer2 = answer2 + "."
        else:
            if j % 2 == 1:
                answer2 = answer2 + "C"
            else:
                answer2 = answer2 + "."
    answer = answer + answer2 + "\n"
print(answer)