n = gets.to_i
pre_sieve = Array.new(n)
sieve = Array.new(n)
ans = 0
2.upto(n - 1) do |i|
  2.upto(Math.sqrt(i)) do |j|
    if i % j == 0
      pre_sieve[i] = j
      break
    end
  end
  pre_sieve[i] ||= i
end

2.upto(n - 1) do |i|
  h = Hash.new(0)
  x = i
  while x != 1
    h[pre_sieve[x]] += 1
    x /= pre_sieve[x]
  end
  sieve[i] = h
end

2.upto(n - 1) do |i|
  x = 1
  sieve[i].each_value do |j|
    x *= (j + 1)
  end

  ans += x
end

puts ans + 1
