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())
ans = ""
coders = 0
for i in range(n):
    for j in range(n):
        if i % 2 == 1:
            if j % 2 == 0:
                # print(".", end="")
                ans += '.'
            else:
                # print("C", end="")
                ans += 'C'
                coders += 1
        else:
            if j % 2 == 0:
                # print("C", end="")
                ans += 'C'
                coders += 1
            else:
                # print(".", end="")
                ans += '.'
    if i < n-1:            
        ans += '\n'
print(coders)
print(ans)