#include <bits/stdc++.h>
using namespace std;

struct FastIO {
    FastIO() {
        srand(time(NULL));
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        cout.tie(NULL);
        cout.precision(12);
    };
} fastIO_;

template <typename T1, typename T2>
inline ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
    return os << "(" << p.first << ", " << p.second << ")";
}

template <typename T, size_t N>
inline ostream &operator<<(ostream &os, const array<T, N> &a) {
    os << "[";
    int cnt = 0;
    for (auto &val : a) {
        if (cnt++) os << ", ";
        os << val;
    }
    os << "]";
    return os;
}

template <typename T>
inline ostream &operator<<(ostream &os, const vector<T> &v) {
    os << "[";
    int cnt = 0;
    for (auto &val : v) {
        if (cnt++) os << ", ";
        os << val;
    }
    return os << "]";
}

template <typename T>
inline ostream &operator<<(ostream &os, const set<T> &v) {
    os << "{";
    int cnt = 0;
    for (auto &val : v) {
        if (cnt++)
            os << ", ";
        os << val;
    }
    return os << "}";
}

template <typename T>
inline ostream &operator<<(ostream &os, const multiset<T> &v) {
    os << "{";
    int cnt = 0;
    for (auto &val : v) {
        if (cnt++)
            os << ", ";
        os << val;
    }
    return os << "}";
}

template <typename T1, typename T2>
inline ostream &operator<<(ostream &os, const map<T1, T2> &v) {
    os << "[";
    int cnt = 0;
    for (auto &val : v) {
        if (cnt++)
            os << ", ";
        os << val;
    }
    return os << "]";
}

#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char *name, Arg1 &&arg1) {
    cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char *names, Arg1 &&arg1, Args &&... args) {
    const char *comma = strchr(names + 1, ',');
    cerr.write(names, comma - names) << ": " << arg1 << " |";
    __f(comma + 1, args...);
}

// types
#define ll long long
#define ull unsigned long long
#define vi vector<int>
#define vll vector<long long>
#define vvi vector<vector<int>>
#define vs vector<string>
#define vb vector<bool>
#define vvb vector<vector<bool>>
#define vc vector<char>
#define si set<int>
#define mpii map<int, int>
#define pii pair<int, int>
#define pll pair<ll, ll>

// names
#define pb push_back
#define fi first
#define se second
#define mp(a, b) make_pair((a), (b))
#define sz(a) ((int)(a).size())
#define rep(i, s, t) for (int i = (s); i < (t); i++)
#define repn(i, s) for (int i = 0; i < (s); i++)
#define ms(a, b) memset(a, b, sizeof(a))
#define all(a) (a).begin(), (a).end()
#define bit(n, i) (((n) >> (i)) & 1)
#define bitCount(n) __builtin_popcountll((n))

// constants
const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, 1, -1};

// functions
template <class T>
inline bool umin(T &a, const T b) { return b < a ? a = b, 1 : 0; }
template <class T>
inline bool umax(T &a, const T b) { return a < b ? a = b, 1 : 0; }
template <class T>
inline T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }
template <class T>
inline T lcm(T a, T b) { return a / gcd(a, b) * b; }

// =====================================================================================================================

#define maxn 100006
int n;

int solve() {
    int ans = 0;
    for (int i = 1; i < n; i++) {
        int j = (n - 1) / i;
        ans += j;
    }
    return ans;
}

void solve(int _cas) {
    // solve();
    cout << solve() << endl;
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("C.in", "r", stdin);
#endif

    while (cin >> n) solve(1);
}


Measured memory_bytes: 3648