#include <bits/stdc++.h>
using namespace std;
const int MX = 2e6 + 10;
const int mod = 1e9 + 7;
const long long int inf = 1LL << 62;
int dx4[] = {0, 0, -1, 1};
int dy4[] = {1, -1, 0, 0};
int dx[] = {1, 1, 1, 0, 0, -1, -1, -1};
int dy[] = {1, 0, -1, 1, -1, 1, 0, -1};
long long int ar[MX], br[MX];
long long int cum[MX];
int main() {
  long long int n, m, k, q, t, cnt = 0, sum = 0, mx = -inf, mn = inf;
  scanf("%lld", &n);
  sum = 1;
  for (long long int i = 2; i * i <= n; i++) {
    while (n % i == 0) {
      sum += n;
      n /= i;
    }
  }
  if (n > 1) sum += n;
  printf("%lld\n", sum);
  return 0;
}
