#include <bits/stdc++.h>
using namespace std;
void solve() {
  int m, n;
  cin >> m >> n;
  vector<long long> a(m), b(n);
  for (int i = 0; i < m; ++i) {
    cin >> a[i];
  }
  for (int i = 0; i < n; ++i) {
    cin >> b[i];
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  long long sum_a = accumulate(a.begin(), a.end(), 0LL),
            sum_b = accumulate(b.begin(), b.end(), 0LL);
  long long ans_1 = sum_a, ans_2 = sum_b;
  for (int i = 0; i < n - 1; ++i) {
    ans_1 += min(sum_a, b[i]);
  }
  for (int i = 0; i < m - 1; ++i) {
    ans_2 += min(sum_b, a[i]);
  }
  cout << min(ans_1, ans_2) << endl;
}
int main() {
  {
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
  }
  solve();
  return 0;
}
