/** 	Author: Apoorva Mittal  **/
/**   Published: 19/09/2020 17:57:36 **/
#include <bits/stdc++.h>
using namespace std;
#define int long long
//#warning int long long MLE
#define endl "\n"
#define vi vector<int>
#define vvi vector<vector<int>>
#define vii vector<pair<int, int>>
#define rep(i, a, b) for (int i = a; i < b; i++)
#define repd(i, b, a) for (int i = b; i >= a; i--)
#define init(i, k) memset(i, k, sizeof i)
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define all(a) a.begin(), a.end()
#define maxe *max_element
#define mine *min_element
#define pow2(n) (1LL << (n))
#define sz(a) (int)a.size()
#define unq(x) x.erase(unique(x.begin(), x.end()), x.end())
//--------------------------------------------debugging showoff---------------------------------------------------------
#define out(a)                               \
    cout << #a << ": " << endl;              \
    rep(i, 0, a.size()) cout << a[i] << " "; \
    cout << endl;
#define out2d(a, w)                       \
    cout << #a << ": " << endl;           \
    rep(i, 0, a.size())                   \
    {                                     \
        rep(j, 0, a[0].size())            \
                cout                      \
            << setw(w) << a[i][j] << " "; \
        cout << endl;                     \
    }
#define sim template <class c
#define ris return *this
#define dor > deb &operator<<
#define eni(x)                                                                  \
    sim > typename enable_if<sizeof dud<c>(0) x 1, deb &>::type operator<<(c i) \
    {
sim > struct rge
{
    c b, e;
};
sim > rge<c> range(c i, c j) { return rge<c>{i, j}; }
sim > auto dud(c *x) -> decltype(cerr << *x, 0);
sim > char dud(...);
struct deb
{
#ifdef LOCAL
    ~deb()
    {
        cerr << endl;
    }
    eni(!=) cerr << boolalpha << i;
    ris;
} eni(==) ris << range(begin(i), end(i));
}
sim, class b dor(pair<b, c> d)
{
    ris << "(" << d.first << ", " << d.second << ")";
}
sim dor(rge<c> d)
{
    *this << "[";
    for (auto it = d.b; it != d.e; ++it)
        *this << ", " + 2 * (it == d.b) << *it;
    ris << "]";
}
#else
    sim dor(const c &)
    {
        ris;
    }
#endif
}
;
#define show(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
// -DLOCAL
//--------------------------------------------useless stuff---------------------------------------------------------------------

#define speed                     \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0)
#define flush fflush(stdout);
#define lb lower_bound
#define ub upper_bound
#define precise(x) cout << fixed << showpoint << setprecision(x);
#define total1(x) __builtin_popcountll(x)
#define left1(x) __builtin_clzll(x)  // "63-right1(x)" to find 0 based index of first set bit from left
#define right1(x) __builtin_ctzll(x) // to find 0 based index of first set bit from right
#define gcd(a, b) __gcd(a, b)
#define n2b(n, b) bitset<b>(n).to_string()

template <class T>
T &chmin(T &a, const T &b)
{
    return a = min(a, b);
}
template <class T>
T &chmax(T &a, const T &b) { return a = max(a, b); }
const int dx[8] = {0, 1, -1, 0, 1, 1, -1, -1};
const int dy[8] = {1, 0, 0, -1, 1, -1, -1, 1};
//------------------------------------------------------------------------------------------------------------------------------
const int mod = 1e9 + 7; //1000000007
// ====== Useful functions begin ======
inline int add(int a, int b) { return ((a % mod) + (b % mod)) % mod; }
inline int sub(int a, int b) { return ((a % mod) - (b % mod) + mod) % mod; }
inline int mul(int a, int b) { return ((a % mod) * (b % mod)) % mod; }
// ====== Useful functions end ======
template <typename T>
istream &operator>>(istream &is, vector<T> &vec)
{
    for (auto &v : vec)
        is >> v;
    return is;
}
//--------------------------------------------------------------------------------------------------------------------------------
const double PI = acos(-1.0);
const long long inf = 1e18; //1000000000000000000
const int maxn = 1e3 + 5;
//--------------------------------------------------------------------------------------------------------------------------------

void solve()
{
    int n;
    cin >> n;
    vi spf(n + 1);
    rep(i, 0, n + 1) spf[i] = i;
    for (int i = 2; i * i <= n; i++)
    {
        if (spf[i] == i)
        {
            for (int j = i * i; j <= n; j += i)
            {
                if (spf[j] == j)
                {
                    spf[j] = i;
                }
            }
        }
    }
    deb()<<show(spf);
    int ans = 0;
    for (int N = 1; N <= n - 1; N++)
    {
        int div = 1;

        map<int, int> fact;
        int num = N;
        while (num > 1)
        {
            fact[spf[num]]++;
            num /= spf[num];
        }
        deb()<<show(N);
        deb()<<show(fact);
        for (auto itr : fact)
        {
            div *= (itr.ss + 1);
        }
        // if (div & 1)
        // {
        //     ans += (div - 1) * 2 + 1;
        // }
        // else
        // {
        //     ans += div * 2;
        // }
        ans+=div;
    }
    cout<<ans<<endl;
    // int ans=0;
    // for(int N=2;N<=n-1;N++)
    // {
    //     int num = N;
    //     int div=1;
    //     for(int i=2;i*i<=num;i++)
    //     {
    //         int cnt=0;
    //         while(num%i==0)
    //         {
    //             num/=i;
    //             cnt++;
    //         }
    //         div*=(cnt+1);
    //     }
    //     if(num>1)
    //     {
    //         div*=2;
    //     }
    //     if(div&1)
    //     {
    //         ans+=(div-1)*2+1;

    //     }
    //     else{
    //         ans+=div*2;
    //     }

    // }
}
signed main()
{
#ifndef ONLINE_JUDGE
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stderr);
#endif // ONLINE_JUDGE

    speed;
    int t = 1;
    //cin >> t;

    for (int tt = 1; tt <= t; tt++)
    {
        // cout<<"Case #"<<tt<<": ";
        solve();
    }

    //CERTAIN STUFF to REMEMBER::
    //1.Check integer overflow
    //2.Check edge case n=1 probable <----------  don't take it lightly, if this will be the reason you'll collapse
    //3.If conditions can be checked without bits, then never check with bits, never try to be oversmart!
    //4.WA can come bcz of very silly things ->  base case, if with bits,bla bla
    //5. MLE? -> #define int long long
    //6. When it's getting too complex till C, consider starting afresh, you might be going in a wrong direction
    //7.long long!!
}

Measured memory_bytes: 11088