#include <bits/stdc++.h>
#define range(i, l, r) for(long long int (i) = (l); (i) < (r); (i)++)
#define reversed_range(i, l, r) for (long long 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 << "[";
    if (v.size() == 0) return 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 << "{";
    if (s.begin() == s.end()) return os << "}";
    auto it_first_item = s.begin();
    os << *it_first_item;
    for (auto it = ++it_first_item; it != s.end(); it++) {
        os << ", " << *it;
    }
    return os << "}";
}

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

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

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

lint pow(lint num, lint e, lint MOD) {
    lint res = 1;
    lint cur_num = num;
    while (e) {
        if (e & 1) {
            res *= cur_num;
            res %= MOD;
        }
        cur_num *= cur_num;
        cur_num %= MOD;
        e >>= 1;
    }
    return res;
}


int main() {
    cin.tie(0); cout.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    lint N, M, Q; cin >> N >> M >> Q;
    vec<vec<lint>> quadruplets(Q);
    range(i, 0, Q) {
        lint a, b, c, d; cin >> a >> b >> c >> d;
        a--; b--;
        quadruplets.at(i) = {a, b, c, d};
    }
    lint ans = 0;
    function<void(vec<lint>&,lint)> calculate_score_for_all_sequences = [&](vec<lint>& cur_seq, lint cur_idx) {
        if (cur_idx == N) {
            lint score = 0;
            range(i, 0, Q) {
                lint a = quadruplets.at(i).at(0), b = quadruplets.at(i).at(1), c = quadruplets.at(i).at(2), d = quadruplets.at(i).at(3);
                if (cur_seq.at(b) - cur_seq.at(a) == c) score += d;
            }
            ans = max(ans, score);
            return;
        }
        lint lb = cur_idx == 0 ? 1 : cur_seq.at(cur_idx - 1);
        range(d, lb, M + 1) {
            cur_seq.at(cur_idx) = d;
            calculate_score_for_all_sequences(cur_seq, cur_idx + 1);
        }
        return;
    };
    vec<lint> cur_seq(N);
    calculate_score_for_all_sequences(cur_seq, 0);
    cout << ans << "\n";
}

Measured memory_bytes: 3564