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 n & 1:
    max_coders = ((n - 1) ** 2) // 2 + n
else:
    max_coders = (n ** 2) // 2

print(max_coders)
for i in range(n):
    for j in range(n):
        if (i & 1 and j & 1) or (not(i & 1) and not(j & 1)):
            print('C', end=' ')
        else:
            print('.', end=' ')
    print()
