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).
# Description of the problem can be found at http://codeforces.com/problemset/problem/384/A

n = int(input())

t = 0
l_o = list()
for i in range(n):
    l_c = list()
    for j in range(n):
        if (i % 2 + j) % 2 == 0:
            t += 1
            l_c.append("C")
        else:
            l_c.append(".")
    l_o.append(l_c)
    
print(t)
print("\n".join("".join(l_c) for l_c in l_o))