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).
'''HackerRank: Coder'''

if __name__ == '__main__':
    n = int(input())
    if n % 2 == 0:
        print(int(n * n / 2))
    else:
        print(int((n * n + 1) / 2))

    arr = ['C', '.'] * n
    for i in range(n):
        if i % 2 == 1:
            print(*arr[1:n+1], sep='')
        else:
            print(*arr[:n], sep='')
