#include <bits/stdc++.h>
using namespace std;
int n, m;
int a[100003];
int b[100003];
int main() {
  scanf("%d %d", &n, &m);
  int i;
  for (i = 0; i < n; i++) scanf("%d", &a[i]);
  for (i = 0; i < m; i++) scanf("%d", &b[i]);
  long long res1 = 0;
  long long res2 = 0;
  long long sum1 = 0;
  long long sum2 = 0;
  for (i = 0; i < n; i++) sum1 += a[i];
  for (i = 0; i < m; i++) sum2 += b[i];
  int ind = 0;
  for (i = 1; i < n; i++)
    if (a[i] > a[ind]) ind = i;
  swap(a[ind], a[n - 1]);
  ind = 0;
  for (i = 1; i < m; i++)
    if (b[i] > b[ind]) ind = i;
  swap(b[ind], b[m - 1]);
  res1 = sum1;
  res2 = sum2;
  for (i = 0; i < m - 1; i++) res1 += min(sum1, (long long)b[i]);
  for (i = 0; i < n - 1; i++) res2 += min(sum2, (long long)a[i]);
  printf("%I64d\n", min(res1, res2));
  return 0;
}
