#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
const long double EPS = 1e-10;
const long long INF = 1e18;
const long double PI = acos(-1.0L);
long long N, M, P;
vector<pair<long long, long long> > tmpa, tmpb;
vector<pair<long long, pair<long long, long long> > > c;
vector<pair<long long, long long> > a, b;
long long ans = -1e18;
struct LazySegmentTree {
 private:
  int n;
  vector<long long> node, lazy;

 public:
  LazySegmentTree(vector<long long> v) {
    int sz = (int)v.size();
    n = 1;
    while (n < sz) n *= 2;
    node.resize(2 * n - 1);
    lazy.resize(2 * n - 1, 0);
    for (int i = 0; i < sz; i++) node[i + n - 1] = v[i];
    for (int i = n - 2; i >= 0; i--)
      node[i] = max(node[i * 2 + 1], node[i * 2 + 2]);
  }
  void eval(int k, int l, int r) {
    if (lazy[k] != 0) {
      node[k] += lazy[k];
      if (r - l > 1) {
        lazy[2 * k + 1] += lazy[k];
        lazy[2 * k + 2] += lazy[k];
      }
      lazy[k] = 0;
    }
  }
  void add(int a, int b, long long x, int k = 0, int l = 0, int r = -1) {
    if (r < 0) r = n;
    eval(k, l, r);
    if (b <= l || r <= a) return;
    if (a <= l && r <= b) {
      lazy[k] += x;
      eval(k, l, r);
    } else {
      add(a, b, x, 2 * k + 1, l, (l + r) / 2);
      add(a, b, x, 2 * k + 2, (l + r) / 2, r);
      node[k] = max(node[2 * k + 1], node[2 * k + 2]);
    }
  }
  long long getmax(int a, int b, int k = 0, int l = 0, int r = -1) {
    if (r < 0) r = n;
    eval(k, l, r);
    if (b <= l || r <= a) return -INF;
    if (a <= l && r <= b) return node[k];
    long long vl = getmax(a, b, 2 * k + 1, l, (l + r) / 2);
    long long vr = getmax(a, b, 2 * k + 2, (l + r) / 2, r);
    return max(vl, vr);
  }
};
void print(LazySegmentTree seg) {
  for (int i = 0; i < M; i++) {
    cerr << seg.getmax(i, i + 1) << " ";
  }
  cerr << endl;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cin >> N >> M >> P;
  tmpa.resize(N);
  tmpb.resize(M);
  c.resize(P);
  for (int i = 0; i < N; i++) cin >> tmpa[i].first >> tmpa[i].second;
  for (int i = 0; i < M; i++) cin >> tmpb[i].first >> tmpb[i].second;
  for (int i = 0; i < P; i++) {
    cin >> c[i].first >> c[i].second.first >> c[i].second.second;
  }
  sort(tmpa.begin(), tmpa.end());
  sort(tmpb.begin(), tmpb.end());
  sort(c.begin(), c.end());
  for (int i = 0; i < N; i++) {
    while (!a.empty() and a.back().second >= tmpa[i].second) a.pop_back();
    a.push_back(tmpa[i]);
  }
  for (int i = 0; i < M; i++) {
    while (!b.empty() and b.back().second >= tmpb[i].second) b.pop_back();
    b.push_back(tmpb[i]);
  }
  b.push_back({1e17, 1e17});
  N = a.size();
  M = b.size();
  vector<long long> INIT;
  for (int i = 0; i < M; i++) {
    INIT.push_back(-b[i].second);
  }
  LazySegmentTree seg(INIT);
  int monster = 0;
  for (int i = 0; i < N; i++) {
    while (monster != P and c[monster].first < a[i].first) {
      pair<long long, long long> tmp = {c[monster].second.first, 1e18};
      auto itr = lower_bound(b.begin(), b.end(), tmp);
      int idx = distance(b.begin(), itr);
      seg.add(idx, M, c[monster].second.second);
      monster++;
    }
    long long now = seg.getmax(0, M);
    chmax(ans, now - a[i].second);
  }
  cout << ans << endl;
  return 0;
}
