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 sys
import math
import bisect

def main():
    n = int(input())
    A = [0] * 2
    for i in range(n):
        for j in range(n):
            val = (i + j) % 2
            A[val] += 1
    print(max(A))
    if A[0] >= A[1]:
        for i in range(n):
            B = ['.'] * n
            for j in range(n):
                if (i + j) % 2 == 0:
                    B[j] = 'C'
            print(''.join(B))
    else:
        for i in range(n):
            B = ['.'] * n
            for j in range(n):
                if (i + j) % 2 == 1:
                    B[j] = 'C'
            print(''.join(B))

if __name__ == "__main__":
    main()
