#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 3;
int n, m, ida, idb;
long long a[maxn], b[maxn], res = 0, mxa = 0, mxb = 0;
void work(long long *a, long long *b, int n, int m, int id) {
  long long sum = 0;
  for (int i = 0; i < m; ++i) sum += b[i];
  res = sum;
  for (int i = 0; i < n; ++i) {
    if (id == i) continue;
    res += min(sum, a[i]);
  }
}
int main() {
  ios::sync_with_stdio(false);
  cin >> n >> m;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    if (a[i] > mxa) {
      ida = i;
      mxa = a[i];
    }
  }
  for (int i = 0; i < m; ++i) {
    cin >> b[i];
    if (b[i] > mxb) {
      idb = i;
      mxb = b[i];
    }
  }
  if (mxa > mxb)
    work(a, b, n, m, ida);
  else
    work(b, a, m, n, idb);
  cout << res << endl;
  return 0;
}
