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).
z=int(input())
if z %2==0:
     print(z*(z//2))
else:
   print(((z*z)//2)+1)   
 
for i in range(z):
    for c in range(z):
        if i%2==0:
            if c%2==0:
                print("C",end='')
            else:
                print(".",end='')
        else:
            if c%2==0:
                print(".",end='')
            else:
                print("C",end='')  

    print()
