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())
if n % 2 == 0:
    print(n**2 //2)
else:
    print( n ** 2 // 2 + 1)
d = [['.'] * n for i in range(n)]
for i in range(n):
    for j in range(n):
        if i % 2 != 0 and j % 2 != 0:
            d[i][j] = 'C'
        if i % 2 == 0 and j % 2 == 0:
            d[i][j] = 'C'
for i in d:
    print(*i,sep = '')