N = gets.to_i
Inf = 10 ** 6

nums = []

for i in 1..Inf do
  nums[i-1] = 0
end

for i in 1..Inf do
  j = 1
  while i * j <= Inf do
    nums[i*j-1] += 1
    j += 1
  end
end

ans = 0
for i in 1..(N-1) do
  ans += nums[N-i-1]
end

puts ans