#include <bits/stdc++.h>
#define range(i, l, r) for(int (i) = (l); (i) < (r); (i)++)
#define reversed_range(i, l, r) for (int (i) = (r) - 1; (i) >= l; (i)--)
using namespace std;
template <typename T>
using vec = vector<T>;
using lint = long long;
using ulint = unsigned long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;

template <typename S, typename T>
ostream& operator <<(ostream& os, pair<S, T> p) {
    os << "(";
    os << p.first << ", " << p.second;
    return os << ")";
}

template <typename T>
ostream& operator <<(ostream& os, vec<T> v) {
    os << "[";
    for (int i = 0; i < v.size() - 1; i++) {
        os << v.at(i) << ", ";
    }
    return os << v.at(v.size() - 1) << "]";
}

template <typename T>
ostream& operator <<(ostream& os, set<T>& s) {
    os << "{";
    auto it_first_item = s.begin();
    cout << *it_first_item;
    for (auto it = ++it_first_item; it != s.end(); it++) {
        cout << ", " << *it;
    }
    return cout << "}";
}

template <typename T>
ostream& operator <<(ostream& os, unordered_set<T>& s) {
    os << "{";
    auto it_first_item = s.begin();
    cout << *it_first_item;
    for (auto it = ++it_first_item; it != s.end(); it++) {
        cout << ", " << *it;
    }
    return cout << "}";
}

template <typename K, typename V>
ostream& operator <<(ostream& os, map<K, V> m) {
    os << "{";
    auto it_first_item = m.begin();
    cout << it_first_item->first << ": " << it_first_item->second;
    for (auto it = ++it_first_item; it != m.end(); it++) {
        cout << ", " << it->first << ": " << it->second;
    }
    return os << "}";
}

template <typename K, typename V>
ostream& operator <<(ostream& os, unordered_map<K, V> m) {
    os << "{";
    auto it_first_item = m.begin();
    cout << it_first_item->first << ": " << it_first_item->second;
    for (auto it = ++it_first_item; it != m.end(); it++) {
        cout << ", " << it->first << ": " << it->second;
    }
    return os << "}";
}

int main() {
    cin.tie(0); cout.tie(0);
    ios::sync_with_stdio(false);
    lint N;
    cin >> N;
    vec<lint> a_list(3 * N);
    range(i, 0, 3 * N) cin >> a_list.at(i);

    priority_queue<lint, vec<lint>, greater<lint>> first_half;
    lint cur_sum = 0;
    range(i, 0, N) {
        lint a = a_list.at(i);
        first_half.emplace(a);
        cur_sum += a;
    }
    vec<lint> sum_first_half;
    sum_first_half.emplace_back(cur_sum);
    range(i, N, 2 * N) {
        lint a = a_list.at(i);
        first_half.emplace(a);
        cur_sum += a - first_half.top();
        first_half.pop();
        sum_first_half.emplace_back(cur_sum);
    }
    assert(sum_first_half.size() == N + 1);

    priority_queue<lint> second_half;
    cur_sum = 0;
    for (lint i = 3 * N - 1; i >= 2 * N; i--) {
        lint a = a_list.at(i);
        second_half.emplace(a);
        cur_sum += a;
    }
    vec<lint> sum_second_half;
    sum_second_half.emplace_back(cur_sum);
    for (lint i = 2 * N - 1; i >= N; i--) {
        lint a = a_list.at(i);
        second_half.emplace(a);
        cur_sum += a - second_half.top();
        second_half.pop();
        sum_second_half.emplace_back(cur_sum);
    }
    assert(sum_second_half.size() == N + 1);

    // cout << sum_first_half << "\n";
    // cout << sum_second_half << "\n";
    lint max_score = -(1LL << 62);
    range(i, 0, N + 1) {
        max_score = max(max_score, sum_first_half.at(i) - sum_second_half.at(N - i));
    }
    cout << max_score << "\n";
}

Measured memory_bytes: 6516