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).
def main():
    n = int(input())
    total = (n // 2) * n if n % 2 == 0 \
        else (n // 2) * n + (n + 1) // 2

    print(total)
    for i in range(n):
        s = ''

        if n % 2 == 0:
            s = 'C.' * (n // 2) if i % 2 == 0 \
                else '.C' * (n // 2)
        else:
            s = 'C.' * (n // 2) + 'C' if i % 2 == 0 \
                else '.C' * (n // 2) + '.'

        print(s)


if __name__ == '__main__':
    main()
