using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using static System.Console;
using static System.Math;

namespace AtCoder
{
    public class Program
    {
        const long Mod = 1000000007;
        public static void Main (string[] args)
        {
            new Program ().Solve (new ConsoleInput (Console.In, ' '));
        }

        public void Solve (ConsoleInput cin)
        {
            int N = cin.ReadInt;

            int[] y = new int[1000002];

            for(int i=1;i<1000002;i++){
                y[i] = yakusu(i);
            }

            int C;
            long ans = 0;
            for(C = 1;C<N;C++){
                ans += y[N-C];
            }

            Console.WriteLine(ans);
        }

        public static int yakusu(int n){
            int x=0;

            if(n == 1) return 1;

            for(int i=1;i<Math.Sqrt(n);i++){
                if(n%i == 0) x++;
            }

            if(Math.Sqrt(n) ==(int)Math.Sqrt(n))  return 2*x + 1;
            else return 2*x;
        }
        public static long CombinationMod (long m, long n)
        {
            var a = 1L;
            var b = 1L;
            for (long i = 1; i <= n; i++)
            {
                a = (a * (m - i + 1)) % Mod;
                b = (b * i) % Mod;
            }

            return ModDiv (a, b) % Mod;
        }
        static long ModDiv (long x1, long x2)
        {
            long bb = ModPow (x2, Mod - 2);
            return (x1 * bb) % Mod;
        }

        static long ModPow (long x1, long x2)
        {
            long ans = 1;
            while (x2 > 0)
            {
                if (x2 % 2 == 1)
                {
                    ans = (ans * x1) % Mod;
                }
                x2 /= 2;
                if (x2 == 0) break;
                x1 = (x1 * x1) % Mod;
            }
            return ans % Mod;
        }
    }

    public class ConsoleInput
    {
        private readonly System.IO.TextReader _stream;
        private char _separator = ' ';
        private Queue<string> inputStream;
        public ConsoleInput (System.IO.TextReader stream, char separator = ' ')
        {
            this._separator = separator;
            this._stream = stream;
            inputStream = new Queue<string> ();
        }
        public string Read
        {
            get
            {
                if (inputStream.Count != 0) return inputStream.Dequeue ();
                string[] tmp = _stream.ReadLine ().Split (_separator);
                for (int i = 0; i < tmp.Length; ++i)
                    inputStream.Enqueue (tmp[i]);
                return inputStream.Dequeue ();
            }
        }
        public string ReadLine { get { return _stream.ReadLine (); } }
        public int ReadInt { get { return int.Parse (Read); } }
        public long ReadLong { get { return long.Parse (Read); } }
        public double ReadDouble { get { return double.Parse (Read); } }
        public string[] ReadStrArray (long N) { var ret = new string[N]; for (long i = 0; i < N; ++i) ret[i] = Read; return ret; }
        public int[] ReadIntArray (long N) { var ret = new int[N]; for (long i = 0; i < N; ++i) ret[i] = ReadInt; return ret; }
        public long[] ReadLongArray (long N) { var ret = new long[N]; for (long i = 0; i < N; ++i) ret[i] = ReadLong; return ret; }
    }
}

Measured memory_bytes: 31784