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 == 0:
    print(int(n**2/2))
else:
    print(int(n**2/2)+1)

for i in range(1,n+1):
    s = ''
    if i%2 != 0:
        for j in range(1,n+1):
            if j%2 != 0:
                s = s+'C'
            else:
                s = s+'.'
    else:
        for j in range(1,n+1):
            if j%2 !=0:
                s = s+'.'
            else:
                s = s+'C'
    print(s)
        
    
