#include <bits/stdc++.h>
using namespace std;
int n, m, p;
pair<int, int> wea[200005];
map<int, int> arm;
pair<pair<int, int>, int> mon[200005];
long long tree[1000000 * 4];
long long lazy[1000000 * 4];
void build(int node, int a, int b) {
  tree[node] = -1000000000000LL;
  if (a == b) return;
  build(node * 2, a, (a + b) / 2);
  build(node * 2 + 1, 1 + (a + b) / 2, b);
}
void upd(int node, int a, int b, int i, int j, long long val) {
  if (lazy[node] != 0) {
    tree[node] = tree[node] + lazy[node];
    if (tree[node] < -1000000000000LL) tree[node] = -1000000000000LL;
    if (a != b) {
      lazy[node * 2] = (lazy[node * 2] + lazy[node]);
      lazy[node * 2 + 1] = (lazy[node * 2 + 1] + lazy[node]);
    }
    lazy[node] = 0;
  }
  if (a > b || a > j || b < i || j < i) return;
  if (i <= a && b <= j) {
    tree[node] = tree[node] + val;
    if (tree[node] < -1000000000000LL) tree[node] = -1000000000000LL;
    if (a != b) {
      lazy[node * 2] = (lazy[node * 2] + val);
      lazy[node * 2 + 1] = (lazy[node * 2 + 1] + val);
    }
    return;
  }
  upd(node * 2, a, (a + b) / 2, i, j, val);
  upd(node * 2 + 1, 1 + (a + b) / 2, b, i, j, val);
  tree[node] = max(tree[node * 2], tree[node * 2 + 1]);
}
long long que(int node, int a, int b, int i, int j) {
  if (lazy[node] != 0) {
    tree[node] = tree[node] + lazy[node];
    if (a != b) {
      lazy[node * 2] = (lazy[node * 2] + lazy[node]);
      lazy[node * 2 + 1] = (lazy[node * 2 + 1] + lazy[node]);
    }
    lazy[node] = 0;
  }
  if (a > b || a > j || b < i) return 0;
  if (a >= i && b <= j) return tree[node];
  long long q1 = que(node * 2, a, (a + b) / 2, i, j);
  long long q2 = que(node * 2 + 1, 1 + (a + b) / 2, b, i, j);
  return max(q1, q2);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cin >> n >> m >> p;
  for (long long i = 0; i < (signed)(n); i++) {
    cin >> wea[i].first >> wea[i].second;
  }
  for (long long i = 0; i < (signed)(m); i++) {
    int b, cb;
    cin >> b >> cb;
    if (arm.count(b)) {
      arm[b] = min(arm[b], cb);
    } else {
      arm[b] = cb;
    }
  }
  for (long long i = 0; i < (signed)(p); i++) {
    cin >> mon[i].first.first >> mon[i].first.second >> mon[i].second;
  }
  sort(wea, wea + n);
  sort(mon, mon + p);
  build(1, 1, 1000000);
  for (auto u : arm) {
    upd(1, 1, 1000000, u.first, u.first, 1000000000000LL - u.second);
  }
  int cw = 0, cm = 0;
  long long mx = -1000000000000LL;
  for (long long i = (1); i <= (signed)(1000000); i++) {
    while (wea[cw].first == i) {
      long long val = que(1, 1, 1000000, 1, 1000000);
      long long tot = val - wea[cw].second;
      mx = max(mx, tot);
      ++cw;
    }
    while (mon[cm].first.first == i) {
      upd(1, 1, 1000000, mon[cm].first.second + 1, 1000000, mon[cm].second);
      ++cm;
    }
  }
  cout << mx << "\n";
  return 0;
}
