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).
try:
    n=int(input())
    ans=(n*n)//2
    print(ans)
    for i in range(1,n+1):
        
        for j in range(1,n+1):
            if j%2!=0 and i%2!=0 or j%2==0 and i%2==0:
                print("C",end="")
            else:
                print(".",end="")
        print("")
except:
    print(n)