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).
def li():
    return list(map(int,input().split()))
def gi(n):
    return [list(map(int,input().split())) for _ in range(n)]

# File input

# import sys
# sys.stdin = open('user.txt','r')

n = int(input())
cnt = 0
ans = []
for i in range(n):
    x = ''
    for j in range(n):
        if i % 2 == 0 and j % 2 == 0:
            x += 'C'
            cnt += 1
        elif i % 2 == 0 and j % 2:
            x += '.'
        elif i % 2 and j % 2 == 0:
            x += '.'
        else:
            x += 'C'
            cnt += 1
    ans.append(x)
print(cnt)
for r in ans:
    print(r)