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).
import math
n=int(input())
arr = []
if n%2 == 0:
    print(str(int((n/2)*n)))
    for z in range(n):
        line= ['.' for i in range(n)]
        for i in range(len(line)):
            if z%2 == 0 and i%2==0:
                line[i]='C'
            elif z%2 !=0 and i%2 != 0:
                line[i]='C'
        arr.append(line)
    for a in arr:
        print(''.join(a))
else:
    s=0
    for i in range(n):
        if i % 2 == 0:
            s+= math.ceil(n/2)
        else:
            s+= math.ceil(n/2) -1
    print(str(s))

    for z in range(n):
        line= ['.' for i in range(n)]
        for i in range(len(line)):
            if z%2 == 0 and i%2==0:
                line[i]='C'
            elif z%2 !=0 and i%2 != 0:
                line[i]='C'
        arr.append(line)
    for a in arr:
        print(''.join(a))