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())
r1 = 'C.' * (n//2)
r2 = '.C' * (n//2)
if n%2 == 0 :
    print( n * n // 2 )
    print((r1+'\n'+r2+'\n') * (n//2) )
else :
    print(n*(n//2+1) - n//2)
    r1 += 'C'
    r2 += '.'
    print((r1+'\n'+r2+'\n') * (n//2) +r1 )