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())
s=""
p=[]
s1=0
for i in range(n):
    if i%2==0:
        for j in range(n):
            if j%2==0:
                #print("C",end="")
                s+="C"
                s1+=1
            else:
               # print(".",end="")
               s+="."
        p+=[s]
        s=""
    else:
        for j in range(n):
            if j%2==0:
                #print(".",end="")
                s+="."
                
            else:
                #print("C",end="")
                s+="C"
                s1+=1
        p+=[s]
        s=""
print(s1)
for i in p:
    print(i)
