#include <iostream>
#include <vector>
#include <algorithm>
#include <set>
using namespace std;
using ll = long long;
struct road
{
ll n;
ll i1;
ll i2;
int t; //0 = horizontal = A, 1 = vertical = B
};
bool operator < (road A, road B)
{
if(A.n*(B.i2 - B.i1) != B.n*(A.i2 - A.i1))
return A.n*(B.i2 - B.i1) < B.n*(A.i2 - A.i1);
else if(A.t != B.t)
return A.t < B.t;
else
return A.i1 < B.i1;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int H, W;
cin >> H >> W;
ll A[1+H], B[1+W];
for(ll i = 1; i <= H; i++) cin >> A[i];
for(ll j = 1; j <= W; j++) cin >> B[j];
set<road> R;
for(ll i = 1; i < H; i++)
R.insert({A[i] - A[i+1], i, i+1, 0});
for(ll j = 1; j < W; j++)
R.insert({B[j] - B[j+1], j, j+1, 1});
set<ll> I, J; //alive indices, where there is a valid road.
for(ll i = 1; i <= H; i++) I.insert(i);
for(ll j = 1; j <= W; j++) J.insert(j);
ll ci = 1, cj = 1;
ll cost = 0;
// for(road r : R) cerr << r.t << ' ' << r.n << '/' << r.i2-r.i1 << '\n';
// cerr << "road = \n";
// for(auto r : R) cerr << r.n << ' ' << r.i1 << ' ' << r.i2 << ' ' << r.t << '\n';
while(!(ci == H && cj == W))
{
// cerr << "\n\n\n";
if(*I.begin() > ci)
{
cost += B[*J.begin()] * (*I.begin() - ci);
ci = *I.begin();
// cerr << "go down\n";
continue;
}
if(*J.begin() > cj)
{
cost += A[*I.begin()] * (*J.begin() - cj);
cj = *J.begin();
// cerr << "go right\n";
continue;
}
road r = *R.rbegin();
R.erase(r);
// cerr << "erase\n";
if(r.t == 0)
{
ll ri = r.i1;
ll rnxt = r.i2;
// cerr << "remove horizontal road " << ri << '\n';
I.erase(ri);
auto it = I.lower_bound(ri);
if(it == I.begin()) continue;
it--;
ll rprv = *it;
R.erase({A[rprv] - A[ri], rprv, ri, 0});
R.insert({A[rprv] - A[rnxt], rprv, rnxt, 0});
// cerr << "insert\n";
}
else
{
ll ri = r.i1;
ll rnxt = r.i2;
// cerr << "remove vertical road " << ri << '\n';
J.erase(ri);
auto it = J.lower_bound(ri);
if(it == J.begin()) continue;
it--;
ll rprv = *it;
R.erase({B[rprv] - B[ri], rprv, ri, 1});
R.insert({B[rprv] - B[rnxt], rprv, rnxt, 1});
// cerr << "insert\n";
}
// cerr << "road = \n";
// for(auto r : R) cerr << r.n << ' ' << r.i1 << ' ' << r.i2 << ' ' << r.t << '\n';
}
cout << cost << '\n';
}
