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).
a=int(input())
if(a%2==0):
    print(a**2//2)
else:
    print((a**2+1)//2)
for i in range(0,a):
    if(i%2==0):
        for j in range(0,a):
            if(j%2==0):
                print("C",end="")
            else:
                print(".",end="")
        print()
    else:
        for j in range(0,a):
            if(j%2==0):
                print(".",end="")
            else:
                print("C",end="")
        print()