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