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())
if n%2==0:
    print((n*n)//2)
else:
    print((n*n)//2+1)
s=''
s2=''
for i in range(n):
    if i%2==0:
        s+='C'
        s2+='.'
    else:
        s2+='C'
        s+='.'
for i in range(n//2):
    print(s)
    print(s2)
if n%2==1:
    print(s)