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())

matrix = []
for i in range(n):
    if i%2 == 0:
        row = 'C.'*(n//2) + 'C'*(1 if n%2 != 0 else 0)
    else:
        row = '.C'*(n//2) + '.'*(1 if n%2 != 0 else 0)
    matrix.append(row)
    
print(n*(n//2))
for j in range(n):
    print(matrix[j])