#include <bits/stdc++.h>
using namespace std;
long long a[100020], b[100020];
int main() {
  int m, n;
  scanf("%d%d", &m, &n);
  long long sum1 = 0, sum2 = 0, s1 = 0, s2 = 0, Max1 = 0, Max2 = 0;
  for (int i = 1; i <= m; i++) {
    scanf("%I64d", &a[i]);
    sum1 += a[i];
    if (a[i] > Max1) {
      Max1 = a[i];
      s1 = i;
    }
  }
  for (int i = 1; i <= n; i++) {
    scanf("%I64d", &b[i]);
    sum2 += b[i];
    if (b[i] > Max2) {
      Max2 = b[i];
      s2 = i;
    }
  }
  long long ans1 = sum1 * n, ans2 = sum2 * m;
  for (int i = 1; i <= m; i++) {
    if (i != s1 && a[i] < sum2) ans2 = ans2 - sum2 + a[i];
  }
  for (int i = 1; i <= n; i++) {
    if (i != s2 && b[i] < sum1) ans1 = ans1 - sum1 + b[i];
  }
  if (ans1 > ans2)
    printf("%I64d\n", ans2);
  else
    printf("%I64d\n", ans1);
  return 0;
}
