#include <bits/stdc++.h>

#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define rep(i,n) for(ll i=0,i##_len=(n);i<i##_len;i++)
#define brep(i,a,b) for(ll i=(a),i##_len=(b);i<=i##_len;i++)
#define rrep(i,n) ll i=(n);ll now=-1;while(i--&&(now++||1))
#define xrep(i,n) for(ll i=1,i##_len=(n);i<=i##_len;i++)
#define Yes(n) cout<<((n)?YES:NO)<<'\n'
#define rYes(n) cout<<((n)?YES:NO)<<'\n';return
#define Sort(v) sort(all(v))
#define rSort(v) sort(all(v)); reverse(all(v))
#define Unique(v) (v).erase(unique(all(v)),(v).end())
#define eb emplace_back

using namespace std;
using ll = long long;
using vll = vector<ll>;
using vbl = vector<bool>;
using vint = vector<int>;
using vvll = vector<vll>;
using vstr = vector<string>;

// --- functions which take 1 argument ---
static inline void ignore_ret(int x){x++;}
template<class T> inline int sgn(T x){return (x>0)-(x<0);}
template<class T> inline ll factorial(T n){if(n==0)return 1;ll r=1;for(T i=2;i<=n;i++)r*=i;return r;}
template<class T> inline map<T,T> factorize(T n){map<T,T>r;for(T i=2;i*i<=n;i++){while(n%i==0){r[i]++;n/=i;}}if(n!=1)r[n]=1;return r;}

// --- functions which take 2 arguments ---
template<class T> inline bool chmax(T&a,const T&b){if(a<b){a=b;return 1;}return 0;}
template<class T> inline bool chmin(T&a,const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T> inline T nPr(T n,T k){if(n<k||n<0||k<0)return 0;T r=1;for(T i=n-k+1;i<=n;i++)r*=i;return r;}
template<class T> inline T nCr(T n,T k){if(n<k||n<0||k<0)return 0;T r=1;k=min(k,n-k);for(T i=n-k+1;i<=n;i++)r*=i;return r/factorial(k);}

// --- functions which take vector(s) as argument(s) ---
template<class T> inline void print(vector<T>v){cout<<"[ ";for(auto x:v)cout<<x<<' ';cout<<"]\n";}
template<class T> inline T min(vector<T>v){return *min_element(all(v));}
template<class T> inline T max(vector<T>v){return *max_element(all(v));}
template<class T> inline ll sum(vector<T>v){return reduce(all(v),0LL);}
template<class T> inline T gcd(vector<T>v){T r=v[0];for(T i=1;i<v.size();i++)r=gcd(r,v[i]);return r;}
template<class T> inline T lcm(vector<T>v){T r=v[0];for(T i=1;i<v.size();i++)r=lcm(r,v[i]);return r;}
template<class T> inline double abs(vector<T>v){return sqrt(reduce(all(v),0.0,[](int s,int v){return s+=v*v;}));}
template<class T> inline T vector_add(T u,T v){ll s=u.size();if(s>v.size())return {};T r;rep(i,s)r.eb(u[i]+v[i]);return r;}
template<class T> inline T vector_subtract(T u,T v){ll s=u.size();if(s>v.size())return {};T r;rep(i,s)r.eb(u[i]-v[i]);return r;}
template<class T> inline T dot_product(vector<T>u,vector<T>v){if(u.size()<v.size())return 0;T r=0;for(T i=0;i<u.size();i++)r+=u[i]*v[i];return r;}
template<class T> inline T cross_product(T u,T v){T r(3);r[0]=u[1]*v[2]-u[2]*v[1];r[1]=u[2]*v[0]-u[0]*v[2];r[2]=u[0]*v[1]-u[1]*v[0];return r;}

// --- Template ends here ---

void solve(ll N, ll M, ll Q, vector<ll> a, vector<ll> b, vector<ll> c, vector<ll> d) {
  vint P(N + M - 1, 0);
  brep(i, M - 1, N + M - 2) P.at(i) = 1;

  int ans = 0;
  do {
    vint X; int cnt = 1;
    for (auto x: P) {
      if (x == 0) cnt++;
      else X.eb(cnt);
    }
    int pts = 0;
    rep(i, Q) {
      if (X.at(b.at(i) - 1) - X.at(a.at(i) - 1) == c.at(i)) pts += d.at(i);
    }

    chmax(ans, pts);
  } while (next_permutation(all(P)));

  cout << ans << endl;
}

int main() {
  ll N;
  ignore_ret(scanf("%lld",&N));
  ll M;
  ignore_ret(scanf("%lld",&M));
  ll Q;
  ignore_ret(scanf("%lld",&Q));
  vector<ll> a(Q);
  vector<ll> b(Q);
  vector<ll> c(Q);
  vector<ll> d(Q);
  for(int i = 0 ; i < Q ; i++){
    ignore_ret(scanf("%lld",&a[i]));
    ignore_ret(scanf("%lld",&b[i]));
    ignore_ret(scanf("%lld",&c[i]));
    ignore_ret(scanf("%lld",&d[i]));
  }
  solve(N, M, Q, move(a), move(b), move(c), move(d));
  return 0;
}


Measured memory_bytes: 3608