#include <bits/stdc++.h>
using namespace std;

#define pii  pair<int, int>
#define vi vector<int >
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define x first
#define y second
#define sz(x) (x).size()
#define all(x) (x).begin(), (x).end() //Forward traversal
#define rall(x) (x).rbegin, (x).rend() //reverse traversal

#define ll long long
#define ld long double

const ld EPS = 10e-9;
const int INF = 1e9 + 5;
const long long INFLL = (ll)INF * (ll)INF;
const ll MOD = 1e9 + 7;
const ld PI = 3.14159265358979323846;

template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v)
{
    os << "[";
    for (int i = 0; i < (int)v.size(); ++i) {
        os << v[i];
        if (i != (int)v.size() - 1)
            os << ", ";
    }
    os << "]\n";
    return os;
}

template <typename T>
ostream& operator<<(ostream& os, const set<T>& v)
{
    os << "{";
    for (const auto& it : v) {
        os << it;
        if (it != *v.rbegin())
            os << ", ";
    }
    os << "}\n";
    return os;
}

template <typename T>
ostream& operator<<(ostream& os, const unordered_set<T>& v)
{
    os << "{";
    for (const auto& it : v) {
        os << it;
        if (it != *v.rbegin())
            os << ", ";
    }
    os << "}\n";
    return os;
}

template <typename T, typename S>
ostream& operator<<(ostream& os, const map<T, S>& v)
{
    os << "{";
    for (const auto& it : v) {
        os << it.first << " : "
           << it.second;

        if( it != *v.rbegin())
            os  << ", ";
    }

    os << "}\n";
    return os;
}

template <typename T, typename S>
ostream& operator<<(ostream& os, const unordered_map<T, S>& v)
{
    os << "{";
    for (const auto& it : v) {
        os << it.first << " : "
           << it.second;

        if( it != *v.rbegin())
            os  << ", ";
    }

    os << "}\n";
    return os;
}

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

#define DEBUG

#ifdef DEBUG
#define debug(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
    cerr << name << " : " << arg1;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
    const char* comma = strchr(names + 1, ',');cerr.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...);
}
#else
#define debug(...)
#endif


// __gcd(x, y)

vector<ll> A;
vector<ll> B;
vector<ll> C;
vector<ll> D;
void rec(int M, int N, vector<int>& seq, int start, ll& score)
{
    if(seq.size() == N)
    {
        //decide about max
        ll curr = 0;
        for(int i = 0; i < A.size(); i++)
        {

            if(B[i]-1 < N && A[i]-1 < N && (seq[B[i]-1] - seq[A[i]-1] == C[i]))
            {
                curr += D[i];
            }
        }

        score = max(score, curr);

        return;
    }

    for(int i = start; i <= M; i++)
    {
        seq.push_back(i);
        rec(M, N, seq, i, score);
        seq.pop_back();
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int N, M, Q;
    cin >> N >> M >> Q;


//    A.pb(0); B.pb(0); C.pb(0); D.pb(0);
    for(int i = 1; i <= Q; i++)
    {
        int a, b, c, d;
        cin >> a >> b >> c >> d;
        A.pb(a);
        B.pb(b);
        C.pb(c);
        D.pb(d);
    }

    vector<int> seq;
    ll score = 0;
//    seq.pb(0);
    rec(M, N, seq, 1, score);

    cout << score << endl;
    return 0;
}



Measured memory_bytes: 3664