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())
c=0
for i in range(n):
    if(i%2==0):
        for j  in range(n):
            if(j%2==0):
                c=c+1
    else:
        for j  in range(n):
            if(j%2!=0):
                c=c+1
print(c)
for i in range(n):
    if(i%2==0):
        for j  in range(n):
            if(j%2==0 and j!=n-1):
                print('C',end='')
            elif(j%2!=0 and j!=n-1):
                print('.',end='')
            else:
                print('C' if j%2==0 else '.')
    else:
        for j  in range(n):
            if(j%2!=0 and j!=n-1):
                print('C',end='')
            elif(j%2==0 and j!=n-1):
                print('.',end='')
            else:
                print('C' if j%2!=0 else '.')