#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 5;
int n, m, p;
long long int tree[4 * N], lazy[N * 4];
int cnt[N + 5];
void update(int node, int start, int end, int l, int r, long long int val) {
  if (l > r) return;
  if (start == l && end == r) {
    tree[node] += val;
    lazy[node] += val;
    return;
  }
  lazy[2 * node] += lazy[node];
  lazy[2 * node + 1] += lazy[node];
  tree[node * 2] += lazy[node];
  tree[2 * node + 1] += lazy[node];
  lazy[node] = 0;
  int mid = (start + end) / 2;
  update(2 * node, start, mid, l, min(r, mid), val);
  update(2 * node + 1, mid + 1, end, max(l, mid + 1), r, val);
  tree[node] = max(tree[2 * node], tree[2 * node + 1]);
}
long long int get(int node, int start, int end, int l, int r) {
  if (l > r) return -1000000;
  if (l <= start && end <= r) return tree[node];
  lazy[2 * node] += lazy[node];
  lazy[2 * node + 1] += lazy[node];
  tree[node * 2] += lazy[node];
  tree[2 * node + 1] += lazy[node];
  lazy[node] = 0;
  int mid = (start + end) / 2;
  long long int a = get(2 * node, start, mid, l, min(r, mid));
  long long int b = get(2 * node + 1, mid + 1, end, max(l, mid + 1), r);
  return max(a, b);
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m >> p;
  vector<pair<long long int, long long int>> a, b;
  for (int i = 0; i < n; i++) {
    long long int x, y;
    cin >> x >> y;
    a.push_back({x, y});
  }
  sort(a.begin(), a.end());
  for (int i = 0; i < m; i++) {
    long long int x, y;
    cin >> x >> y;
    b.push_back({x, y});
  }
  sort(b.begin(), b.end());
  for (int i = 0; i < m; i++) {
    if (!cnt[b[i].first]) {
      cnt[b[i].first] = 1;
      update(1, 1, N, b[i].first, b[i].first, -b[i].second);
    }
  }
  for (int i = 1; i <= N; i++) {
    if (!cnt[i]) {
      update(1, 1, N, i, i, -1e18);
    }
  }
  long long int ans = -a[0].second - b[0].second;
  vector<tuple<long long int, long long int, long long int>> v;
  for (int i = 0; i < p; i++) {
    long long int x, y, z;
    cin >> x >> y >> z;
    v.push_back(make_tuple(x, y, z));
  }
  sort(v.begin(), v.end());
  long long int curr = ans;
  int j = 0;
  for (int i = 0; i < n; i++) {
    long long int x, y, z;
    tie(x, y, z) = v[j];
    while (j < p && x < a[i].first) {
      update(1, 1, N, y + 1, N, z);
      j++;
      tie(x, y, z) = v[j];
    }
    long long int curr = tree[1] - a[i].second;
    ans = max(ans, curr);
  }
  cout << ans;
}
