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())

coders = 0
start = 0

for i in range(n):
    for j in range(start, n, 2):
        if i % 2 == 0:
            start = 0
        else:
            start = 1

        coders += 1


print(coders)


for i in range(n):
    for j in range(n):
        if i % 2 == 0:
            if j % 2 == 0:
                print("C", end="")
            else:
                print(".", end="")
        else:
            if j % 2 != 0:
                print("C", end="")
            else:
                print(".", end="")

    print()

