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())

L=[]
ans = 0

for i in range(n) :
    s = ""
    for j in range(n) :
        if ((i % 2) == (j % 2)) :
            s = s + "C"
            ans += 1
        else :
            s = s + "."
    L.append(s)

print(ans)
for s in L :
    print(s)
