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
a = int(input())
b = []
print(ceil((a*a)/2))
for i in range(1, a+1):
    if i % 2 == 1:
        for j in range(0, ceil(a/2)):
            b.append('c')
            b.append('.')
    else:
        for j in range(0, ceil(a/2)):
            b.append('.')
            b.append('c')
    if a % 2 == 1:
        b.pop(-1)
    print(*b, sep='')
    b = []