#include <bits/stdc++.h>
#include <unistd.h>

using namespace std;

#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}


typedef long long ll;

#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const ll MOD = 1000000007;
//const ll MOD = 998244353;
const double pi = 3.14159265358979323846;
#define Sp(p) cout<<setprecision(15)<< fixed<<p<<endl;
int dx[4] = { -1,0, 1,0 }, dy[4] = { 0,1,0,-1 };
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
// #define mp make_pair
//#define endl '\n'


int main() {
  ll w, h;
  cin >> h >> w;
  vl p(h), q(w);
  priority_queue<ll, vector<ll>, greater<ll>> ppq, qpq;
  rep (i, h) {
    cin >> p[i];
    ppq.push(p[i]);
  }
  rep (i, w) {
    cin >> q[i];
    qpq.push(q[i]);
  }
  
  ll cnt = 0;
  ll pcnt = 0, qcnt = 0;
  ll ans = 0;
  
  ppq.push(INF);
  qpq.push(INF);
  while (cnt < (h + 1) * (w + 1) - 1) {
    //DEBUG(cnt);
    //DEBUG(ans);
    if (ppq.top() <= qpq.top()) {
      ll yasu = ppq.top();
      //DEBUG("P");
      //      DEBUG(yasu);
      ppq.pop();
      if (cnt + (w + 1 - qcnt) <= (h + 1) * (w + 1) - 1) {
        ans += yasu * (w + 1 - qcnt);
        cnt += (w + 1 - qcnt);
      }
      else {
        ans += yasu * ((h + 1) * (w + 1) - 1 - cnt);
        cnt = (h + 1) * (w + 1) - 1;
      }
      pcnt++;
    }
    else {
      ll yasu = qpq.top();
      //DEBUG("Q");
      //DEBUG(yasu);
      qpq.pop();
      if (cnt + (h + 1 - pcnt) <= (h + 1) * (w + 1) - 1) {
        ans += yasu * (h + 1 - pcnt);
        cnt += (h + 1 - pcnt);
      }
      else {
        ans += yasu * ((h + 1) * (w + 1) - 1 - cnt);
        cnt = (h + 1) * (w + 1) - 1;
      }
      qcnt++;
    }
  }

  cout << ans << endl;
}


Measured memory_bytes: 4084