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).
"""
https://codeforces.com/problemset/problem/384/A
"""

def solve(n):
    is_coder = True
    r = []
    c = 0
    for _ in range(n):
        l = ''
        for _ in range(n):
            if is_coder:
                l += 'C'
                c += 1
            else:
                l += '.'
            is_coder = not is_coder
        if n % 2 == 0:
            is_coder = not is_coder
        r.append(l)
    return c, r

def print_res(c, r):
    print(c)
    for l in r:
        print(l)


n = int(input())
print_res(*solve(n))
