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).
n = int(input())
tab = []
k = 0
for i in range(n):
    tab.append([])
    for j in range(n):
        tab[k].append('0')
    k += 1
def attack(tab, x, y, n):
    if x >= 0 and x < n and y >= 0 and y < n:
        tab[y][x] = '.'
num = 0
for y in range(n):
    for x in range(n):
        if tab[y][x] == '0':
            num += 1
            tab[y][x] = 'C'
            attack(tab, x + 1, y, n)
            attack(tab, x - 1, y, n)
            attack(tab, x, y + 1, n)
            attack(tab, x, y - 1, n)
print (num)
for y in range(n):
    for x in range(n):
        print ("%c" % tab[y][x], end='')
    print ()