#include    <iostream>
#include    <fstream>

#define     NMAX 1000000
#define     ll long long

using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");

ll n;

int fractii(int n)
{
    ll cnt = 1;
    for(int p = 1; p <= n; p++)
    {
        for(int q = 1; q <= n; q++)
        {
            if(p/q == 0) continue;
            else cnt+=1;
        }
    }
    return cnt;
}

int main()
{
    fin >> n;
    fout << fractii(n);
    return 0;
}