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())

if not n%2:
    num = ((n // 2) ** 2) * 2
else:
    num = (n // 2) ** 2 + (n // 2 + 1) ** 2

print(num)

for i in range(n):
    if not i%2:
        print('C.'*(n//2) + 'C'*(n % 2))
    else:
        print('.C'*(n//2) + '.'*(n % 2))
