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%2==0):
    p=n*n//2
else:
    p=(n*(n//2))+(n//2+1)
print(p)
c1=[]
c2=[]
for i in range(n):
    if(i%2==0):
        c1.append("C")
        c2.append(".")
    else:
        c1.append(".")
        c2.append("C")
c3=''.join(c1)
c4=''.join(c2)
s=1
while(n):
    if(s==1):
        print(c3)
    else:
        print(c4)
    s=1-s
    n-=1