#include <bits/stdc++.h>
using namespace std;
int n, m;
int a[100005], b[100005];
int main() {
  int i;
  long long int ans, sum, num;
  sum = 0;
  ans = 0;
  num = 0;
  scanf("%d%d", &n, &m);
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    sum += a[i];
  }
  for (i = 0; i < m; i++) {
    scanf("%d", &b[i]);
    ans += b[i];
  }
  sort(a, a + n);
  sort(b, b + m);
  if (a[n - 1] < b[m - 1]) {
    for (i = 0; i < m - 1; i++) {
      if (sum > b[i])
        num += b[i];
      else
        num += sum;
    }
    num += sum;
  } else {
    for (i = 0; i < n - 1; i++) {
      if (ans > a[i])
        num += a[i];
      else
        num += ans;
    }
    num += ans;
  }
  printf("%lld\n", num);
  return 0;
}
