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;n=int(input());print((math.ceil(n/2)**2+(n//2)**2));k="."*n;p="."*n;h=1
for i in range(n):
    if i%2!=0:k=k[:i]+"c"+k[i+1:]
    else:p=p[:i]+"c"+p[i+1:]
while(h<=n):print(p if h%2 else k );h+=1