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())
a='C.'
b='.C'
lst=[]
for i in range(1,n+1):
    if(i%2!=0):
        s=a*n
        w=s[:n]
        lst.append(w)
    else:
        s=b*n
        w=s[:n]
        lst.append(w)
if(n%2==0):
    v=((n*n)//2)
else:
    v=((n*n)//2)+1
print(v)
for j in lst:
    print(j)
    
