#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
int n, m, xi;
using vec = vector<ll>;
vec xs[2];
vec maxx = {0, 0};
vec maxi = {0, 0};
int main() {
  cin >> n >> m;
  vec ns = {n, m};
  for (ll k = 0; k < 2; k++) {
    for (ll i = 0; i < ns.at(k); i++) {
      cin >> xi;
      xs[k].push_back(xi);
      if (xi > maxx.at(k)) {
        maxx.at(k) = xi;
        maxi.at(k) = i;
      }
    }
  }
  ll a = 1, b = 0;
  if (maxx.at(0) > maxx.at(1)) {
    a = 0;
    b = 1;
  }
  ll sum = 0;
  for (auto &&x : xs[b]) sum += x;
  ll sumB = sum;
  for (ll i = 0; i < ns[a]; i++) {
    if (i != maxi.at(a)) {
      sum += min(sumB, xs[a].at(i));
    }
  }
  cout << sum << endl;
  return 0;
}
