def f(n)
return 0 if n <= 1
return 1 if n == 2
return 3 if n == 3
if n % 2 == 0
k = f(n/2)
return 2 * k + n * n / 4
else
return f(n / 2) + f(n / 2 + 1) + ((n / 2) * (n / 2 + 1))
end
end
n = gets.to_i
puts f(n)