#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int m, n;
  cin >> m >> n;
  vector<long long> a;
  vector<long long> b;
  long long temp;
  for (int i = 0; i < m; ++i) {
    cin >> temp;
    a.push_back(temp);
  }
  for (int i = 0; i < n; ++i) {
    cin >> temp;
    b.push_back(temp);
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  if (a.back() > b.back()) {
    long long sb = 0;
    for (auto it : b) sb += it;
    long long res = sb;
    for (auto it = a.begin(); it != a.end() - 1; ++it) {
      res += min(sb, *it);
    }
    cout << res << endl;
  } else {
    long long sa = 0;
    for (auto it : a) sa += it;
    long long res = sa;
    for (auto it = b.begin(); it != b.end() - 1; ++it) {
      res += min(sa, *it);
    }
    cout << res << endl;
  }
  return 0;
}
