#include <bits/stdc++.h>
using namespace std;
const double PI = 3.14159265358979323846;
const double eps = (1e-10);
int isGreater(long double x, long double y) {
  if (abs(x - y) < eps) return 0;
  if (x > y) return 1;
  return -1;
}
int weapons, armors, monsters;
const int MAX_N = 2e5 + 5, MAX_D = 1e6 + 5;
int b[MAX_N], cb[MAX_N];
pair<int, int> a[MAX_N];
struct Monster {
  int attack, defense, gain;
  bool operator<(const Monster &other) const { return defense < other.defense; }
};
Monster m[MAX_N];
long long defCost[MAX_D];
long long t[4 * MAX_D], lazy[4 * MAX_D];
void apply(int p, int l, int r) {
  if (lazy[p]) {
    t[p] += lazy[p];
    if (l != r) {
      lazy[2 * p] += lazy[p];
      lazy[2 * p + 1] += lazy[p];
    }
    lazy[p] = 0;
  }
}
void update(int stq, int enq, long long v, int p = 1, int l = 0,
            int r = MAX_D - 1) {
  if (l >= stq && r <= enq) {
    lazy[p] += v;
    apply(p, l, r);
    return;
  }
  apply(p, l, r);
  if (l > enq || r < stq) return;
  int mid = (l + r) / 2;
  update(stq, enq, v, 2 * p, l, mid);
  update(stq, enq, v, 2 * p + 1, mid + 1, r);
  t[p] = max(t[2 * p], t[2 * p + 1]);
}
long long get() {
  apply(1, 0, MAX_D - 1);
  t[1] = max(t[2], t[3]);
  return t[1];
}
int solve() {
  sort(a, a + weapons);
  sort(m, m + monsters);
  long long ans = 0LL + -a[0].second + get();
  for (int i = 0, j = 0; i < weapons; ++i) {
    while (j < monsters && a[i].first > m[j].defense) {
      update(m[j].attack + 1, MAX_D - 1, m[j].gain);
      ++j;
    }
    ans = max(ans, 0LL + -a[i].second + get());
  }
  return ans;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> weapons >> armors >> monsters;
  for (int i = 0; i < weapons; ++i) cin >> a[i].first >> a[i].second;
  for (int i = 0; i < MAX_D; ++i) defCost[i] = 1e17;
  for (int i = 0; i < armors; ++i) {
    cin >> b[i] >> cb[i];
    defCost[b[i]] = min(defCost[b[i]], 1LL * cb[i]);
  }
  for (int i = 0; i < monsters; ++i)
    cin >> m[i].defense >> m[i].attack >> m[i].gain;
  for (int i = 0; i < MAX_D; ++i) {
    update(i, i, -defCost[i]);
  }
  cout << solve() << '\n';
  return 0;
}
