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 math
length = int(input())

base = "C."

even = ""
odd = ""
result = 0
if(length % 2 == 0):
    result = (length/2) * length
else:
    result = int((length- 1) / 2)
    result = result + (result + 1)
    result = math.ceil(result * (length / 2.0))
    
print(int(result)) 
    
if( length % 2 == 1):
    even = (base * int((length- 1) / 2)) + 'C'
    base = ".C"
    odd = ((base * int((length- 1) / 2))) + '.'
else:
    even = (base * int(length /2))
    base = ".C"
    odd= (base * int(length/2) )
    
for i in range(1,length +1):
    if(i % 2== 1):
        print(even)
    else:
        print(odd)
    
