#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
int n, m, p;
struct node {
  int a, c;
  node(int x = 0) { a = x, c = 0; }
} wp[N], ar[N];
bool operator<(node a, node b) { return a.a < b.a; }
struct node2 {
  int x, y, z;
} mon[N];
bool operator<(node2 a, node2 b) { return a.x < b.x; }
int ans = 1 << 31;
int mx[N << 2], tag[N << 2];
inline void add(int k, int v) {
  mx[k] += v;
  tag[k] += v;
}
inline void pushup(int k) { mx[k] = max(mx[k << 1], mx[k << 1 | 1]); }
inline void pushdwn(int k) {
  add(k << 1, tag[k]);
  add(k << 1 | 1, tag[k]);
  tag[k] = 0;
}
void Build(int k, int l, int r) {
  if (l == r) {
    mx[k] = -ar[l].c;
    return;
  }
  int mid = l + r >> 1;
  Build(k << 1, l, mid);
  Build(k << 1 | 1, mid + 1, r);
  pushup(k);
  return;
}
void Modify(int k, int l, int r, int qx, int qy, int qv) {
  if (qx <= l && r <= qy) return add(k, qv);
  pushdwn(k);
  int mid = l + r >> 1;
  if (qx <= mid) Modify(k << 1, l, mid, qx, qy, qv);
  if (mid < qy) Modify(k << 1 | 1, mid + 1, r, qx, qy, qv);
  pushup(k);
  return;
}
int main() {
  scanf("%d%d%d", &n, &m, &p);
  for (int i = 1; i <= n; i++) scanf("%d%d", &wp[i].a, &wp[i].c);
  for (int i = 1; i <= m; i++) scanf("%d%d", &ar[i].a, &ar[i].c);
  sort(wp + 1, wp + n + 1);
  sort(ar + 1, ar + m + 1);
  for (int i = 1; i <= p; i++) scanf("%d%d%d", &mon[i].x, &mon[i].y, &mon[i].z);
  sort(mon + 1, mon + p + 1);
  Build(1, 1, m);
  for (int i = 1, s1 = 0; i <= n; i++) {
    while (s1 < p && mon[s1 + 1].x < wp[i].a) {
      s1++;
      int w = upper_bound(ar + 1, ar + m + 1, node(mon[s1].y)) - ar;
      if (w <= m) Modify(1, 1, m, w, m, mon[s1].z);
    }
    ans = max(ans, mx[1] - wp[i].c);
  }
  printf("%d\n", ans);
  return 0;
}
