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).
a=int(input())
if a*a%2==0:
    print(a*a//2)
else:
    print((a*a//2)+1)
n=0    
for i in range(a):
    if n==0: 
        if a%2>0:
            print('C.'*(a//2),'C',sep='')
        else:
            print('C.'*(a//2))
        n+=1
    else:
        n=0
        if a%2>0:
            print('.C'*(a//2),'.',sep='')
        else:
            print('.C'*(a//2))
    