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
alnum={chr(i):j for i,j in zip(range(97,123),range(1,27))}
q=lambda:map(int,input().split())
qi=lambda:int(input())
qs=lambda:input().split()
n,=q()
a=[['C' if not j%2 else '.' for j in range(n)] if not i%2 else ['C' if j%2 else '.' for j in range(n)] for i in range(n)]
print(ceil(n**2/2))
for i in a:
    for j in i:
        print(j,end='')
    print()