#include <bits/stdc++.h>

using namespace std;
using ll = unsigned long long;

int main()
{
    ll n1, n2;
    cin >> n1 >> n2;
    vector<ll> z1(n1);
    vector<ll> z2(n2);
    for (int i = 0; i < n1; i++)
    {
        cin >> z1.at(i);
    }
    for (int i = 0; i < n2; i++)
    {
        cin >> z2.at(i);
    }
    sort(z1.begin(), z1.end());
    ll s = 0;
    for (int i = 0; i < n2; i++)
    {
        vector<ll>::const_iterator x;
        x = lower_bound(z1.begin(), z1.end(), z2.at(i));
        ll var = x - z1.begin();
        s += var - z2.at(i);
    }
    cout << s << endl;
    return 0;
}