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())
row1 = ('C.' * (n // 2))
row2 = ('.C' * (n // 2))

if (n % 2 == 0):
    print(n * n // 2)
    res = (row1 + '\n' + row2 + '\n') * (n // 2)
    print(res)
else:
    print(n * (n // 2 + 1) - n // 2)
    row1 += 'C'
    row2 += '.'
    res = (row1 + '\n' + row2 + '\n') * (n // 2) + row1
    print(res)