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())
lol=[]
x='C..'
l=[]
o=0
for i in range(n):
    y=x[i%3]
    l.append(y)
    if y=='C':
        o+=1
lol.append(l)
for i in range(1,n):
    l=[]
    for j in range(n):
        if lol[i-1][j]!='C':
            if l[j-1]!='C':
                o+=1
                l.append('C')
            else:
                l.append('.')
        else:
            l.append('.')
    lol.append(l)
print(o)
for i in lol:
    for j in i:
        print(j,end='')
    print()
