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**2):
    if i % N == 0 and i != 0:
        print()
    if i % 2 == 0:
        print('C',end = '')
    else:
        print('.',end = '')
    i+=1
 