#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
long long powmod(long long a, long long b, long long MOD) {
  long long ans = 1;
  while (b) {
    if (b % 2) ans = ans * a % MOD;
    a = a * a % MOD;
    b /= 2;
  }
  return ans;
}
const int N = 1e5 + 11;
int n, m;
long long a[N], b[N];
long long A[N], B[N];
int main() {
  ios::sync_with_stdio(false);
  cin >> n >> m;
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= m; i++) cin >> b[i];
  sort(a + 1, a + 1 + n);
  sort(b + 1, b + 1 + m);
  for (int i = 1; i <= n; i++) A[i] = A[i - 1] + a[i];
  for (int i = 1; i <= m; i++) B[i] = B[i - 1] + b[i];
  long long ans = LLONG_MAX, pre = 0;
  for (int i = n; i >= 1; i--) {
    int pos = upper_bound(b + 1, b + 1 + m, a[i]) - b;
    long long res = B[pos - 1];
    res += 1ll * (m - pos + 1) * a[i];
    pre += res;
    if (ans <=
        pre + (i > 1 ? (B[m] + A[i - 1] - max(a[i - 1], 1ll * b[m])) : 0))
      break;
    ans = pre + (i > 1 ? (B[m] + A[i - 1] - max(a[i - 1], 1ll * b[m])) : 0);
  }
  pre = 0;
  for (int i = m; i >= 1; i--) {
    int pos = upper_bound(a + 1, a + 1 + n, b[i]) - a;
    long long res = A[pos - 1];
    res += 1ll * (n - pos + 1) * b[i];
    pre += res;
    if (ans <=
        pre + (i > 1 ? (A[n] + B[i - 1] - max(b[i - 1], 1ll * a[n])) : 0))
      break;
    ans = pre + (i > 1 ? (A[n] + B[i - 1] - max(b[i - 1], 1ll * a[n])) : 0);
  }
  cout << min({ans, A[n] + B[m - 1], A[n - 1] + B[m]}) << endl;
  return 0;
}
