// C
#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#ifdef __GXX_EXPERIMENTAL_CXX0X__
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif
//#include <bits/stdc++.h>

#define all(v) v.begin(), v.end()
typedef long long ll;
#define rep(i, z, n) for(int i = z; i < n; i++)
//const int INF = 1<<29;
const ll MOD = 1000000007;
#define P pair<int, int>
using namespace std;

/*
vector<pair<int64_t, int64_t>> prime_factorize(int64_t n) {
    vector<pair<int64_t, int64_t>> res;
    for (int64_t p = 2; p * p <= n; p++) {
        if (n % p != 0) continue;
        int num = 0;
        while (n % p == 0){
            num++;
            n /= p;
        }
        res.push_back(make_pair(p, num));
    }
    if (n != 1) res.push_back(make_pair(n, 1));
    return res;
}

int main(){
    ll N;
    cin >> N;
    ll count = 0;
    rep(i, 1, N){
        vector<pair<int64_t, int64_t>> res = prime_factorize(N - i);
        int s = res.size();
        rep(j, 0, s){
            res.at(j).second
        }
    }
    cout << count << endl;
}

*/
template<typename T>
vector<T> smallest_prime_factors(T n) {

    vector<T> spf(n + 1);
    for (int i = 0; i <= n; i++) spf[i] = i;


    for (T i = 2; i * i <= n; i++) {

        // 素数だったら
        if (spf[i] == i) {

            for (T j = i * i; j <= n; j += i) {

                // iを持つ整数かつまだ素数が決まっていないなら
                if (spf[j] == j) {
                    spf[j] = i;
                }
            }
        }
    }

    return spf;
}

int main() {
    ll N;
    cin >> N;
    ll count = 0;
    
    auto spf = smallest_prime_factors(N);
    
    ll ans = 0;
    
    rep(i, 1, N){
        int j = i;
        map<ll, ll> m;
        while(j != 1){
            if(m.count(spf[j])) m[spf[j]]++;
            else m[spf[j]] = 1;
            j /= spf[j];
        }
        ll x = 1;
        for (auto p : m){
            auto value = p.second;
            x *= (value + 1);
        }
        //cout << x << endl;
        ans += x;
    }
    cout << ans << endl;
}


Measured memory_bytes: 11084