#include <bits/stdc++.h>
using namespace std;
#include <algorithm>
// #include <atcoder/all>
#include <ranges>
// using namespace atcoder;

/* alias */
using ull = unsigned long long;
using ll = long long;
using vi = vector<int>;
using vl = vector<long>;
using vll = vector<long long>;
using vvi = vector<vi>;
using vvl = vector<vl>;
using vvll = vector<vll>;
using vs = vector<string>;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vpll = vector<pll>;

/* define short */
#define pb push_back
#define mp make_pair
#define all(obj) (obj).begin(), (obj).end()
#define YESNO(bool)        \
  if (bool) {              \
    cout << "YES" << endl; \
  } else {                 \
    cout << "NO" << endl;  \
  }
#define yesno(bool)        \
  if (bool) {              \
    cout << "yes" << endl; \
  } else {                 \
    cout << "no" << endl;  \
  }
#define YesNo(bool)        \
  if (bool) {              \
    cout << "Yes" << endl; \
  } else {                 \
    cout << "No" << endl;  \
  }

/* REP macro */
#define rep(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define reps(i, a, n) for (ll i = (a); i <= (ll)(n); ++i)

template <typename T>
inline bool chmax(T& a, const T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

// 座標を表す構造体
struct Point {
  int y, x;

  // コンストラクタを追加
  Point(int y_ = 0, int x_ = 0) : y(y_), x(x_) {}

  // <
  bool operator<(const Point& other) const {
    if (y != other.y)
      return y < other.y;
    return x < other.x;
  }

  // == 一致確認
  bool operator==(const Point& other) const {
    return y == other.y && x == other.x;
  }
};

/*
エラトステネスの篩
O(N)未満で素数判定を行う
N以下の整数に対して素数判定
nが素数ならば isp(n)=true、そうでなければ isp(n)=false

参考: https://qiita.com/sakofsuken/items/210e082169daba690570
*/

ll sum = 0;
ll upper;

const ll N = pow(10, 5);
vector<bool> isp(N + 1, true);
// vll add_list;

void sieve() {
  isp[0] = false;
  isp[1] = false;
  for (long long i = 2; pow(i, 2) <= N; i++) {
    if (isp[i]) {
      for (long long j = 2; i * j <= N; j++)
        isp[i * j] = false;
      // nの累乗の総和をとる
      for (long long j = i * i; j <= upper; j *= i) {
        sum += j;
        // add_list.pb(j);
      }
    }
  }
}

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);

  cin >> upper;

  sieve();
  cout << sum << endl;
  return 0;
}