#include <bits/stdc++.h>
using namespace std;
long long modulo(long long base, long long exponent, long long modulus);
long long choose(long long n, long long k);
long long inverse(long long a, long long m);
void build();
void fileio();
long long ncr(long long n, long long r);
const int nax = 1e6 + 10;
const int LG = log2(nax) + 1;
vector<long long> fact(nax);
vector<long long> invfact(nax);
long long mod = 1000000007;
struct monst {
  long long x, y, z;
};
bool comp(monst &a, monst &b) { return a.x < b.x; }
vector<long long> tree1(4 * nax);
vector<long long> lazy(4 * nax);
void update(long long node, long long nl, long long nr, long long l,
            long long r, long long ele, vector<long long> &tree,
            vector<long long> &lazy) {
  if (lazy[node] != 0) {
    tree[node] += lazy[node];
    if (nl != nr) {
      lazy[2 * node + 1] += lazy[node];
      lazy[2 * node + 2] += lazy[node];
    }
    lazy[node] = 0;
  }
  if (nl > nr || l > r || nl > r || l > nr) return;
  if (l <= nl && nr <= r) {
    tree[node] += ele;
    if (nl != nr) {
      lazy[2 * node + 1] += ele;
      lazy[2 * node + 2] += ele;
    }
    return;
  }
  long long mid = (nl + nr) / 2;
  update(2 * node + 1, nl, mid, l, r, ele, tree, lazy);
  update(2 * node + 2, mid + 1, nr, l, r, ele, tree, lazy);
  tree[node] = max(tree[2 * node + 1], tree[2 * node + 2]);
}
long long querry(long long node, long long nl, long long nr, long long l,
                 long long r, vector<long long> &tree,
                 vector<long long> &lazy) {
  if (lazy[node] != 0) {
    tree[node] += lazy[node];
    if (nl != nr) {
      lazy[2 * node + 1] += lazy[node];
      lazy[2 * node + 2] += lazy[node];
    }
    lazy[node] = 0;
  }
  if (nl > nr || l > r || nl > r || l > nr) return INT_MIN;
  if (l <= nl && nr <= r) return tree[node];
  long long mid = (nl + nr) / 2;
  long long p1 = querry(2 * node + 1, nl, mid, l, r, tree, lazy);
  long long p2 = querry(2 * node + 2, mid + 1, nr, l, r, tree, lazy);
  return max(p1, p2);
}
set<pair<long long, long long> > s;
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  build();
  long long n, m, p;
  cin >> n >> m >> p;
  vector<pair<long long, long long> > a(n);
  for (int i = 0; i < n; i++) cin >> a[i].first >> a[i].second;
  vector<pair<long long, long long> > b(m);
  for (int i = 0; i < m; i++) cin >> b[i].first >> b[i].second;
  vector<monst> c(p);
  for (int i = 0; i < p; i++) cin >> c[i].x >> c[i].y >> c[i].z;
  sort(c.begin(), c.end(), comp);
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  vector<long long> suffixmin(m);
  suffixmin[m - 1] = b[m - 1].second;
  for (int i = m - 2; i >= 0; i--) {
    suffixmin[i] = min(suffixmin[i + 1], b[i].second);
  }
  long long last = 0;
  for (int i = 0; i < m; i++) {
    for (int j = last; j <= b[i].first; j++)
      update(0, 0, nax - 1, j, j, -suffixmin[i], tree1, lazy);
    last = b[i].first + 1;
  }
  for (int j = last; j < nax; j++)
    update(0, 0, nax - 1, j, j, INT_MIN, tree1, lazy);
  long long j = 0;
  long long f = INT_MIN;
  long long maxi = 0;
  for (int i = 0; i < n; i++) {
    while (j < p && c[j].x < a[i].first) {
      update(0, 0, nax - 1, c[j].y + 1, nax - 1, c[j].z, tree1, lazy);
      j++;
    }
    f = max(f, tree1[0] - a[i].second);
  }
  cout << f << '\n';
  return 0;
}
long long ncr(long long n, long long r) {
  if (r > n || r < 0 || n < 0) return 0;
  long long ans = fact[n];
  long long temp = (invfact[n - r] * invfact[r]) % mod;
  ans = (ans * temp) % mod;
  return ans;
}
void fileio() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
}
void build() {
  fact[0] = 1;
  invfact[0] = inverse(1, mod);
  for (long long i = 1; i < nax; i++) {
    fact[i] = (fact[i - 1] * i) % mod;
    invfact[i] = inverse(fact[i], mod);
  }
}
long long modulo(long long base, long long exponent, long long modulus) {
  if (modulus == 1) return 0;
  long long result = 1;
  base = base % modulus;
  while (exponent > 0) {
    if (exponent % 2 == 1) {
      result = (result * base) % modulus;
    }
    exponent = exponent >> 1;
    base = (base * base) % modulus;
  }
  return result;
}
long long choose(long long n, long long k) {
  if (k == 0) return 1;
  return (n * choose(n - 1, k - 1)) / k;
}
void EE(long long a, long long b, long long &co1, long long &co2) {
  if (a % b == 0) {
    co1 = 0;
    co2 = 1;
    return;
  }
  EE(b, a % b, co1, co2);
  long long temp = co1;
  co1 = co2;
  co2 = temp - co2 * (a / b);
}
long long inverse(long long a, long long m) {
  long long x, y;
  EE(a, m, x, y);
  if (x < 0) x += m;
  return x;
}
