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).
"""Coder"""

n = int(input())
if n % 2 == 0:
    print(int(n * n / 2))
else:
    print(int((n * n + 1) / 2))
arr = ["C", "."] * n
for i in range(n):
    if i % 2 == 0:
        print(*arr[:n])
    else:
        print(*arr[1:n + 1])
###c.c. -->0
###.c.c -->1
###c.c. -->2
###.c.c -->3