// Author: Klay Thompson
// Problem: P10052 [CCO2022] Double Attendance
// Memory Limit: 1 MB
// Time Limit: 3000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#ifdef dbg
#define D(...) fprintf(stderr, __VA_ARGS__)
#define DD(...) D("[Debug] "#__VA_ARGS__ " = "), \
              debug_helper::debug(__VA_ARGS__), D("\n")
#include "C:\Users\wsyear\Desktop\OI\templates\debug.hpp"
#else
#define D(...) ((void)0)
#define DD(...) ((void)0)
#endif
#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T> void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T> void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 2000010;

int n, m, k, tot = 2000, f[maxn][2][2];
// time, which classroom, the other classroom is seen?
pii a[maxn], b[maxn];

int getid(pii *a, int n, int t) {
  int p = upper_bound(a + 1, a + n + 1, pii(t, 2e9)) - a - 1;
  if (a[p].fi > t || a[p].se < t || p > n) return -1;
  return p;
}

int find(pii *a, int n, int t) {
  int l = 1, r = n, res = n + 1;
  while (l <= r) {
    int mid = (l + r) >> 1;
    if (a[mid].se >= t) res = mid, r = mid - 1;
    else l = mid + 1;
  }
  return res;
}

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  cin >> n >> m >> k;
  rep (i, 1, n) cin >> a[i].fi >> a[i].se, a[i].fi++;
  rep (i, 1, m) cin >> b[i].fi >> b[i].se, b[i].fi++;
  sort(a + 1, a + n + 1), sort(b + 1, b + m + 1);
  rep (i, 1, tot) rep (j, 0, 1) rep (k, 0, 1) f[i][j][k] = -1e9;
  f[1][0][0] = 0;
  if (a[1].fi == 1) f[1][0][0] = 1;
  int ans = 0;
  rep (i, 1, tot) {
    int px = getid(a, n, i), py = getid(b, m, i);
    int nx = upper_bound(a + 1, a + n + 1, pii(i, 2e9)) - a;
    int ny = upper_bound(b + 1, b + m + 1, pii(i, 2e9)) - b;
    int nkx = find(a, n, i + k), nky = find(b, m, i + k);
    if (nx != n + 1) chkmx(f[a[nx].fi][0][0], max(f[i][0][0], f[i][0][1]) + 1);
    if (ny != m + 1) chkmx(f[b[ny].fi][1][0], max(f[i][1][0], f[i][1][1]) + 1);
    if (py != -1 && nky == py) chkmx(f[i + k][1][px != -1 && i + k <= a[px].se], f[i][0][0] + 1);
    else if (nky < m) chkmx(f[max(i + k, b[nky].fi)][1][px != -1 && max(i + k, b[nky].fi) <= a[px].se], max(f[i][0][0], f[i][0][1]) + 1);
    if (px != -1 && nkx == px) chkmx(f[i + k][0][py != -1 && i + k <= b[py].se], f[i][1][0] + 1);
    else if (nkx < n) chkmx(f[max(i + k, a[nkx].fi)][0][py != -1 && max(i + k, a[nkx].fi) <= b[py].se], max(f[i][1][0], f[i][1][1]) + 1);
    ans = max(ans, max(max(f[i][0][0], f[i][0][1]), max(f[i][1][0], f[i][1][1])));
  } 
  cout << ans << '\n';
}