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=input()
n=int(n)
if n%2!=0:
    count=(n*int(n/2))+(int(n/2)+1)
else:
    count=((n/2)**2)*2
print(int(count))
for i in range(n):
    for j in range(n):
        if i%2==0 and j%2==0:
            print("C ",end = '')
        elif i%2==0 and j%2!=0:
            print(". ",end='')
        elif i%2!=0 and j%2==0:
            print(". ", end='')
        else:
            print("C ", end='')
    print("\n")
