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())

max_coders = (n*n)//2 + (n*n)%2
print(max_coders)

for i in range(n):
    row = ""
    for j in range(n):
        if (i+j)%2 == 0 and max_coders > 0:
            row += "C"
            max_coders -= 1
        else:
            row += "."
    print(row)
