#include <bits/stdc++.h>
using namespace std;
template <typename T1, typename T2>
ostream& operator<<(ostream& os, const pair<T1, T2>& a) {
  os << "(" << a.first << ", " << a.second << ")";
  return os;
}
struct LazySegmentTree {
 private:
  int n;
  vector<long long> node, lazy;

 public:
  LazySegmentTree(vector<long long> v) {
    int sz = v.size();
    n = 1;
    while (n < sz) n *= 2;
    node.resize(2 * n - 1, -(1LL << 60));
    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] / (r - l);
      if (r - l > 1) {
        lazy[2 * k + 1] += lazy[k] / 2;
        lazy[2 * k + 2] += lazy[k] / 2;
      }
      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] += (r - l) * 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;
    if (b <= l || r <= a) return -(1LL << 60);
    eval(k, l, r);
    if (a <= l && r <= b) return node[k];
    long long vl = getmax(a, b, k * 2 + 1, l, (l + r) / 2);
    long long vr = getmax(a, b, 2 * k + 2, (l + r) / 2, r);
    return max(vl, vr);
  }
};
struct monster {
  int x, y, z;
  bool operator<(const monster& a) const { return y < a.y; }
};
int main() {
  int n, m, p;
  cin >> n >> m >> p;
  vector<pair<int, int> > a(n), b(m);
  vector<monster> d(p);
  vector<long long> c(1000010, -(1LL << 60));
  for (int i = 0; i < n; ++i) scanf("%d%d", &a[i].first, &a[i].second);
  for (int i = 0; i < m; ++i) scanf("%d%d", &b[i].first, &b[i].second);
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  for (int i = n - 1; i > 0; --i)
    if (a[i].second < a[i - 1].second) a[i - 1].second = a[i].second;
  for (int i = m - 1; i > 0; --i)
    if (b[i].second < b[i - 1].second) b[i - 1].second = b[i].second;
  int r = 0;
  for (int i = 0; i < n; ++i) {
    for (int j = r; j < a[i].first; ++j) c[j] = -a[i].second;
    r = a[i].first;
  }
  LazySegmentTree seg(c);
  for (int i = 0; i < p; ++i) scanf("%d%d%d", &d[i].x, &d[i].y, &d[i].z);
  sort(d.begin(), d.end());
  long long ans = -a[0].second - b[0].second;
  int j = 0;
  for (int i = 0; i < m; ++i) {
    while (j < p && d[j].y < b[i].first) {
      seg.add(d[j].x, 1000010, d[j].z);
      j++;
    }
    ans = max(ans, -b[i].second + seg.getmax(0, 1000010));
  }
  cout << ans << endl;
}
