n = gets.to_i

def divisor(num)
  result = []
  i = 1
  while i <= num do
    remainder = num % i
    if remainder == 0
      result << i
    end
    i += 1
  end
  return result
end

count = 0
for i in (1..n-1) do
  count += divisor(n-i).length
end

puts count