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())

print((n*n)//2+n%2)
s1 = ''.join(['C' if x%2==0 else '.' for x in range(n)])
s2 = ''.join(['C' if x%2==1 else '.' for x in range(n)])
for i in range(n):
    print(s1 if i%2==0 else s2)

