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(inyput())
if n%2==0 :
    print((n*n)/2)
else :
    print((n/2*n)+(n-n/2))
s1="."
s2="C"
for i in range(n-1):
    if i%2==0 :
        s1=s1+"C"
        s2=s2+".";
        
    else :
       s1=s1+"."
       s2=s2+"C"
for i in range(n):
   if i%2==0 :
        print(s2)
   else :
        print(s1)