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