require 'prime'
n = gets.to_i

ans = 1

if n == 2
  puts ans
  exit
end

2.upto(n-1) do |i|
  prime_division = Prime.prime_division(i)
  count = 1
  prime_division.each do |p, e|
    count *= e + 1
  end
  ans += count
end

puts ans
