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/2)*n)
else:
    print((n/2*n/2)+((n-n/2)*(n-n/2)))
for i in range(n):
    if(i%2==0):
        for j in range(n):
            if j%2==0:
                print("C",end='')
            else:
                print(".",end='')
    else:
        for k in range(n):
            if(k%2==1):
                print("C",end='')
            else:
                print(".",end='')
    print("")
