#include <bits/stdc++.h>
using namespace std;
template <typename T>
void read(T& x) {
  x = 0;
  char ch = getchar();
  long long f = 1;
  while (!isdigit(ch)) {
    if (ch == '-') f *= -1;
    ch = getchar();
  }
  while (isdigit(ch)) {
    x = x * 10 + ch - 48;
    ch = getchar();
  }
  x *= f;
}
template <typename T, typename... Args>
void read(T& first, Args&... args) {
  read(first);
  read(args...);
}
template <typename T>
void write(T arg) {
  T x = arg;
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x > 9) {
    write(x / 10);
  }
  putchar(x % 10 + '0');
}
template <typename T, typename... Ts>
void write(T arg, Ts... args) {
  write(arg);
  if (sizeof...(args) != 0) {
    putchar(' ');
    write(args...);
  }
}
using namespace std;
long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); }
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
const int N = 4e5 + 5;
int n, m, p;
long long c[N];
struct Node1 {
  int val;
  long long cost;
  bool operator<(const Node1& no) const { return val < no.val; }
} a[N], b[N];
bool cmp(Node1 x, Node1 y) {
  if (x.val == y.val) return x.cost < y.cost;
  return x.val < y.val;
}
struct Node2 {
  int x, y;
  long long val;
  bool operator<(const Node2& no) const {
    if (x == no.x) return y < no.y;
    return x < no.x;
  }
} mon[N];
struct trNode {
  int l, r;
  long long maxn, val, tag;
} tr[N << 2];
void build(int i, int l, int r) {
  tr[i].l = l, tr[i].r = r;
  tr[i].maxn = tr[i].val = tr[i].tag = 0;
  if (l == r) return;
  int mid = (l + r) >> 1;
  build(i << 1, l, mid);
  build(i << 1 | 1, mid + 1, r);
}
void push_down(int i) {
  if (tr[i].tag) {
    tr[i << 1].tag += tr[i].tag;
    tr[i << 1 | 1].tag += tr[i].tag;
    tr[i << 1].maxn += tr[i].tag;
    tr[i << 1 | 1].maxn += tr[i].tag;
    tr[i].tag = 0;
  }
}
void update(int i, int l, int r, int L, int R, int k) {
  if (l >= L && r <= R) {
    tr[i].maxn += k;
    tr[i].tag += k;
    return;
  }
  push_down(i);
  int mid = (l + r) >> 1;
  if (L <= mid) update(i << 1, l, mid, L, R, k);
  if (R > mid) update(i << 1 | 1, mid + 1, r, L, R, k);
  tr[i].maxn = max(tr[i << 1].maxn, tr[i << 1 | 1].maxn);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m >> p;
  for (int i = 1; i <= n; i++) cin >> a[i].val >> a[i].cost;
  for (int i = 1; i <= m; i++) cin >> b[i].val >> b[i].cost;
  for (int i = 1; i <= p; i++) cin >> mon[i].x >> mon[i].y >> mon[i].val;
  sort(a + 1, a + 1 + n);
  sort(b + 1, b + 1 + m, cmp);
  sort(mon + 1, mon + 1 + p);
  for (int i = 1; i <= m; i++) c[i] = b[i].val;
  int now = 1;
  long long ans = -1e18;
  build(1, 1, m);
  for (int i = 1; i <= m; i++) update(1, 1, m, i, i, -b[i].cost);
  for (int i = 1; i <= n; i++) {
    while (mon[now].x < a[i].val && now <= p) {
      int idx = upper_bound(c + 1, c + 1 + m, mon[now].y) - c;
      update(1, 1, m, idx, m, mon[now].val);
      now++;
    }
    ans = max(ans, tr[1].maxn - a[i].cost);
  }
  cout << ans << endl;
}
