#include <bits/stdc++.h>
using namespace std;
long long int min(long long int a, long long int b) { return a < b ? a : b; }
long long int min(long long int a, long long int b, long long int c) {
  a = min(a, b);
  a = min(a, c);
  return a;
}
long long int max(long long int a, long long int b) { return a > b ? a : b; }
long long int max(long long int a, long long int b, long long int c) {
  a = max(a, b);
  a = max(a, c);
  return a;
}
long long int dsum(long long int n) {
  long long int ans = 0;
  while (n) {
    ans += (n % 10);
    n /= 10;
  }
  return ans;
}
long long int power(long long int a, long long int b) {
  long long int res = 1;
  while (b) {
    if (b & 1) res = res * a;
    a = a * a;
    b >>= 1;
  }
  return res;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v) {
  for (T &t : v) is >> t;
  return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  for (const T &t : v) {
    os << t << " ";
  }
  os << '\n';
  return os;
}
struct pll {
  long long int x, y;
};
bool comp(pll a, pll b) {
  if (a.x == b.x)
    return a.y < b.y;
  else
    return a.x < b.x;
}
void solve(long long int the) {
  char ch;
  double aa, bb, cc, dd, xx;
  string s1, s2, s3, str;
  long long int i, j, k, a, b, c, d, n, m, l, r, x, y, z, low, high, mid,
      sum = 0, ans = 0, temp, t;
  cin >> n;
  ans = n;
  for (i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      a = max(i, n / i);
      ans += a;
      i = 1;
      n = a;
    }
  }
  cout << ans + 1;
}
int main() {
  long long int t = 1, c = 1;
  while (t--) {
    solve(c);
    c++;
  }
  return 0;
}
