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())
    if n%2 == 1:
        print((n//2+1)**2+(n//2)**2)
        for i in range(n):
            if i%2 == 0:
                print('C.'*(n//2)+'C')
            else:
                print('.C'*(n//2)+'.')
            
    else:
        print(n//2*n)
        for i in range(n):
            if i%2 == 0:
                print('C.'*(n//2))
            else:
                print('.C'*(n//2))
main()

