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).
from math import ceil
n = int(input())
list1 = []
for x in range(n):
    list2 = []
    for y in range(n):
       if (x + y) % 2 == 0:
           list2.append("c")
       else:
           list2.append(".")
    list1.append(list2)
print(ceil(n ** 2 / 2))
for n in list1:
    print("".join(n))
