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).
# import os

n = int(input())

c = 0
r = []
for i in range(n):
    if i % 2 == 0:
        if n % 2 == 0:
            r.append('C.'*(n//2))
            c += n//2
        else:
            ss = 'C.'*(n//2)
            r.append(ss[:-1])
            c += n//2
    else:
        if n % 2 == 0:
            r.append('.C'*(n//2))
            c += n//2
        else:
            ss = '.C'*(n//2)
            r.append(ss[:-1])
            c += n//2-1
print(c)
for l in r:
    print(l)
