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

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

final=[ans[a:a+n] for a in range(0,len(ans),n)]
for y in final:
    print(*y,sep="")