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())

cnt = round(N*N/2 + 0.5)
print(cnt)
i = 0
while(i < N):
    j = 0
    while(j < N):
        if j % 2 == 0 and i % 2 == 0:
            print('C',end = '')
        elif j % 2 == 1 and i % 2 == 1:
            print('C',end = '')
        else:
            print('.',end = '')
        j+=1
    i+=1
    print()