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())

    r = ((n + 1)//2)**2 + (n//2)**2

    print(r)

    for i in range(1, n + 1):
        for j in range(1, n + 1):
            if i%2 == j%2:
                print('C', end="")
            else:
                print('.', end="")
        print()

main()