#include <bits/stdc++.h>
using namespace std;
long long spf[31];
long long fac[31];
void sieve() {
  spf[1] = 1;
  for (long long i = 2; i < 31; i++) spf[i] = i;
  for (long long i = 4; i < 31; i += 2) spf[i] = 2;
  for (long long i = 3; i * i < 31; i++) {
    if (spf[i] == i) {
      for (long long j = i * i; j < 31; j += i)
        if (spf[j] == j) spf[j] = i;
    }
  }
}
map<long long, long long> getfactor(long long a) {
  map<long long, long long> m;
  while (a > 1) {
    m[spf[a]]++;
    a /= spf[a];
  }
  return m;
}
long long power(long long x, long long y, long long p) {
  long long res = 1;
  x = x % p;
  if (x == 0) return 0;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
long long gcd(long long a, long long b) {
  if (a == 0) return b;
  return gcd(b % a, a);
}
long long inverse(long long a, long long p) { return power(a, p - 2, p); }
long long ncr(long long n, long long r, long long p) {
  if (r > n) return 0;
  if (r == 0 || r == n) return 1;
  return (fac[n] * inverse(fac[r], p) % p * inverse(fac[n - r], p) % p) % p;
}
void solve() {
  long long n, m, d;
  cin >> n >> m >> d;
  pair<long long, long long> p[n + 1], q[m + 1];
  for (long long i = 1; i <= n; i++) {
    cin >> p[i].first >> p[i].second;
    p[i].second = -p[i].second;
  }
  for (long long i = 1; i <= m; i++) {
    cin >> q[i].first >> q[i].second;
    q[i].second = -q[i].second;
  }
  sort(q + 1, q + m + 1);
  reverse(q + 1, q + m + 1);
  sort(p + 1, p + n + 1);
  reverse(p + 1, p + n + 1);
  long long pre1[m + 5], pre2[m + 5];
  memset(pre1, 0, sizeof(pre1));
  memset(pre2, 0, sizeof(pre2));
  for (long long i = 1; i <= m; i++) {
    pre1[i] = q[i].first + pre1[i - 1];
    pre2[i] = pre2[i - 1] - q[i].second;
  }
  pre1[m + 1] = 1e18;
  pre2[m + 1] = 1e18;
  long long sum = 0, maxi = 0;
  long long tot = 0;
  for (long long i = 1; i <= n && sum < d; i++) {
    tot += p[i].first;
    sum -= p[i].second;
    auto it = upper_bound(pre2, pre2 + m + 2, d - sum) - pre2;
    if (it > 0) it--;
    if (it == 0)
      break;
    else {
      maxi = max(pre1[it] + tot, maxi);
    }
  }
  cout << maxi << '\n';
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long test = 1;
  while (test--) {
    solve();
  }
}
