#include <bits/stdc++.h>
using namespace std;
template <typename T>
class Lazyseg {
 public:
  T left, right;
  T mx, sum, lazy;
  Lazyseg *lChild, *rChild;
  Lazyseg(T l, T r) : left(l), right(r), lazy(0), mx(-1e12), sum(0) {
    if (left != right) {
      T mid = (left + right) / 2;
      lChild = new Lazyseg(left, mid);
      rChild = new Lazyseg(mid + 1, right);
      recal();
    } else {
      sum = -1e12;
    }
  }
  void recal() {
    if (left == right) return;
    mx = max(lChild->mx, rChild->mx);
    sum += lChild->sum + rChild->sum;
  }
  void prop() {
    if (lazy == 0) return;
    if (left == right) {
      sum += lazy;
      mx = sum;
      lazy = 0;
    } else {
      mx += lazy;
      sum += lazy * (right - left + 1);
      lChild->lazy += lazy;
      rChild->lazy += lazy;
      lazy = 0;
    }
  }
  void rangeUpdate(long long int l, long long int r, long long int val) {
    prop();
    if (l > right || r < left) return;
    if (l <= left && r >= right) {
      lazy += val;
      prop();
    } else {
      lChild->rangeUpdate(l, r, val);
      rChild->rangeUpdate(l, r, val);
      recal();
    }
  }
  T rangeQuery(long long int l, long long int r) {
    prop();
    if (l > right || r < left) return -1e18;
    if (l <= left && r >= right) {
      return mx;
    } else {
      return max(lChild->rangeQuery(l, r), rChild->rangeQuery(l, r));
    }
  }
  ~Lazyseg() {
    if (left != right) {
      delete lChild;
      delete rChild;
    }
  }
};
const long long int N = 1e6 + 5;
void solve() {
  long long int n, m, p;
  cin >> n >> m >> p;
  vector<pair<long long int, long long int>> attack, armour;
  for (long long int i = 0; i < (n); i++) {
    long long int a, ca;
    cin >> a >> ca;
    attack.push_back({a, ca});
  }
  for (long long int i = 0; i < (m); i++) {
    long long int b, cb;
    cin >> b >> cb;
    armour.push_back({b, cb});
  }
  vector<vector<long long int>> mon;
  for (long long int i = 0; i < (p); i++) {
    long long int x, y, z;
    cin >> x >> y >> z;
    mon.push_back({x, y, z});
  }
  sort((attack).begin(), (attack).end());
  sort((mon).begin(), (mon).end());
  Lazyseg<long long int> seg(0, N - 1);
  vector<long long int> def(N, 1e12);
  for (long long int i = 0; i < (m); i++) {
    def[armour[i].first] = min(armour[i].second, def[armour[i].first]);
  }
  for (long long int i = 0; i < (N); i++) {
    if (def[i] != 1e12) {
      seg.rangeUpdate(i, i, 1e12 - def[i]);
    }
  }
  long long int ptr = 0;
  long long int ans = -1e12;
  for (long long int i = 0; i < (n); i++) {
    long long int att = attack[i].first;
    while (ptr < p && mon[ptr][0] < att) {
      seg.rangeUpdate(mon[ptr][1] + 1, N - 1, mon[ptr][2]);
      ptr++;
    }
    ans = max(ans, seg.rangeQuery(0, N - 1) - attack[i].second);
  }
  cout << ans << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  ;
  long long int t;
  t = 1;
  while (t--) solve();
  return 0;
}
