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())
s, t = 'C.' * 500, '.C' * 500
if n % 2 == 0:
    print(n * (n // 2))
else:
    print((n - 1) * (n - 1) // 2 + n)
for i in range(n):
    if i % 2 == 0:
        print(s[:n:])
    else:
        print(t[:n:])