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())
l=[]
count1=0
for i in range(n):
    l.append([])
    for j in range(n):
        if(i%2==0 and j%2==0 or (i%2==1 and j%2==1)):
            l[i].append("C")
            count1=count1+1
        
        else:
            l[i].append(".")     
print(count1)
for i in range(len(l)):
    for j in l[i]:
        print(j,end=" ")
    print()

        