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).
from math import ceil

num = int(input())
print(ceil((num*num)/2))
l1 = ""
l2 = ""
for i in range(num):
    if i%2 ==0:
        l1 = l1+"C"
    else:
        l1 = l1+"."

for i in range(num):
    if i%2 ==0:
        l2 = l2+"."
    else:
        l2 = l2+"C"
if num%2==0:
    for i in range(num//2):
        print(l1)
        print(l2)
else:
    for i in range(num//2):
        print(l1)
        print(l2)
    print(l1)