#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, M;
  static int a[100005];
  static int b[100005];
  scanf("%d %d", &N, &M);
  int i;
  long long A, B;
  A = 0;
  B = 0;
  for (i = 0; i < N; i++) {
    scanf("%d", &(a[i]));
    A += (long long)(a[i]);
  }
  for (i = 0; i < M; i++) {
    scanf("%d", &(b[i]));
    B += (long long)(b[i]);
  }
  sort(a, a + N);
  sort(b, b + M);
  long long res = 1000000000000000000LL;
  long long S;
  S = 0LL;
  for (i = 0; i < N; i++) {
    long long temp = S;
    int mult = N - i;
    int part = mult / 10;
    if (part == 0) part = 1;
    while (part <= mult) {
      temp += (B) * (long long)(part);
      mult -= part;
      if (temp > 1000000000000000000LL) break;
    }
    if (temp <= 1000000000000000000LL) {
      temp += (B) * (long long)(mult);
      if (temp < res) res = temp;
    }
    S += (long long)(a[i]);
  }
  S = 0LL;
  for (i = 0; i < M; i++) {
    long long temp = S;
    int mult = M - i;
    int part = mult / 10;
    if (part == 0) part = 1;
    while (part <= mult) {
      temp += (A) * (long long)(part);
      mult -= part;
      if (temp > 1000000000000000000LL) break;
    }
    if (temp <= 1000000000000000000LL) {
      temp += (A) * (long long)(mult);
      if (temp < res) res = temp;
    }
    S += (long long)(b[i]);
  }
  printf("%I64i\n", res);
  return 0;
}
