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).
a = int(input(""))
result = []
for i in range(a):
    result.append(["."]*a)
fs = 'C'
ss = '.'
for i in range(a-1):
    if fs[len(fs)-1] == 'C':
        fs = fs + '.'
    else:
        fs = fs + 'C'
    if ss[len(ss)-1] == 'C':
        ss = ss + '.'
    else:
        ss = ss +'C'

        
temp = 0
if a % 2 == 1:
    print(int(((a*a)+1)/2))
else:
    print(int(((a*a))/2))
for i in range(a):
    if temp == 0:
        print(fs)
        temp = 1
    else:
        print(ss)
        temp = 0
