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())
if (n**2)%2==0:
    print((n**2)//2)
elif (n**2)%2!=0:
    print(((n**2)//2)+1)
b=[]
s=""
for i in range(n):
    for j in range((n//2)+1):
        if i%2==0:
            s+="C."
        else:
            s+=".C"
    b.append(s)
    s=""
c=[]
for p in b:
    c.append(p[0:n])
for l in c:
    print(l)
