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())
a=[]
t=0
for i in range(1,n+1):
    a.append([])
    for j in range(1,n+1):
        if (i+j)%2==0:
            a[len(a)-1].append('C')
            t+=1
        else:
            a[len(a)-1].append('.')
print(t)
for k in a:
    print(*k)

