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