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())
maxm = (n * n + 1) // 2

chessboard = []
for _ in range(n):
    row = []
    for _ in range(n):
        row.append('.')
    chessboard.append(row)
    
for i in range(n):
    for j in range(i % 2, n, 2):
        chessboard[i][j] = 'C'

print(maxm)
for k in chessboard:
    print(''.join(k))