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).
# cook your dish here

n = int(input())

if n%2==0:
    print(int(n*(n/2)))
else:
    print(int((n//2)*(n//2) + (n//2 + 1)*(n//2 + 1)))

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