#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pli pair<ll,int>
#define pil pair<int,ll>
#define fi first
#define se second
#define inf (INT_MAX/2-1)
#define infl (1LL<<60)
#define vi vector<int>
#define vl vector<ll>
#define pb push_back
#define sz(a) ((int)(a).size())
#define all(a) begin(a),end(a)
#define y0 y5656
#define y1 y7878
#define aaa system("pause");
#define dbg(x) std::cerr<<(#x)<<": "<<(x)<<'\n',aaa
#define dbga(x,n) std::cerr<<(#x)<<"[]: ";for(int _=0;_<n;_++)std::cerr<<x[_]<<' ';std::cerr<<'\n',aaa
#define dbgs(x) std::cerr<<(#x)<<"[stl]: ";for(auto _:x)std::cerr<<_<<' ';std::cerr<<'\n',aaa
#define dbgp(x) std::cerr<<(#x)<<": "<<x.fi<<' '<<x.se<<'\n',aaa
#define dbgsp(x) std::cerr<<(#x)<<"[stl pair]:\n";for(auto _:x)std::cerr<<_.fi<<' '<<_.se<<'\n';aaa
#define maxn 50000
#define maxm 100000
#define maxh 1000000

using namespace std;

struct InParser {
  FILE *fin;
  const int DIM = (1<<16);
  char BUFF[(1<<16)+5]; ///invalid use of non-static data member
  int kbu;

  InParser (const char *filename) {
    fin = fopen(filename, "r");
    kbu = DIM;
  }

  ~InParser () {
    fclose(fin);
  }

  inline void reset () {
    if (kbu == DIM) {
      fread(BUFF, 1, DIM, fin);
      kbu = 0;
    }
  }

  template<typename T>
  void read (T &nr) {
    reset();
    nr = 0;
    while (BUFF[kbu] < '0' || BUFF[kbu] > '9') {
      kbu++;
      reset();
    }
    while (BUFF[kbu] >= '0' && BUFF[kbu] <= '9') {
      nr = nr * 10 + BUFF[kbu++] - '0';
      reset();
    }
  }
};

struct AIB {
  int yy[maxh+5];

  int lsb (int x) {
    return x&(-x);
  }

  void upd (int x, int amt) {
    while (x <= maxh+1) {
      yy[x] += amt;
      x += lsb(x);
    }
  }

  int qry (int x) {
    int ans = 0;
    while (x > 0) {
      ans += yy[x];
      x -= lsb(x);
    }
    return ans;
  }
};

pair<pii, bool> queries[4*maxn+5], cpyof_queries[4*maxn+5];
///vreau sa raspund la queriuri tip cate puncte sunt in
///chenarul (0, 0) = stanga jos, (?, ??) = dreapta sus. T/F = adun/scad la raspuns.

pii puncte[maxm+5], cpyof_puncte[maxn+5];
AIB aib;
int fv[maxh+5]; ///pentru sort(puncte, puncte+m); sort(queries, queries+4*n);

int main () {
  InParser inp("ograzi.in");
  FILE *fout = fopen("ograzi.out", "w");

  int n; inp.read<int>(n); ///nr ograzi
  int m; inp.read<int>(m); ///nr oi
  int w; inp.read<int>(w); ///width ograzi
  int h; inp.read<int>(h); ///height ograzi

  int i, j, x, y, z;
  for (i = 0; i < n; i++) {
    inp.read<int>(x);
    inp.read<int>(y);
    x++;
    y++;
    ///(x, y) = coltul stanga jos al unei ograzi.
    queries[4*i]   = make_pair(pii(x+w, y+h), true);
    queries[4*i+1] = make_pair(pii(x+w, y-1), false);
    queries[4*i+2] = make_pair(pii(x-1, y+h), false);
    queries[4*i+3] = make_pair(pii(x-1, y-1), true);
  }

  for (i = 0; i < m; i++) {
    inp.read<int>(puncte[i].fi);
    inp.read<int>(puncte[i].se);
    puncte[i].fi++; ///ca sa fie toate coord >= 1 pt aib.
    puncte[i].se++;
  }

  ///sortez punctele si queriurile crescator dupa Ox, cand vine un query am grija sa am bagate
  ///intr-o SD toate punctele cu X mai mic decat al queryului. trebuie sa intreb SD cate
  ///valori din el sunt mai mici decat un Y, cum valorile sunt mici merge un AIB.

  ///sort(puncte, puncte+m)
  for (i = 0; i < m; i++) fv[puncte[i].fi]++;
  for (i = 1; i <= maxh+1; i++) fv[i] += fv[i-1];
  for (i = 0; i < m; i++) {
    cpyof_puncte[fv[puncte[i].fi]-1] = puncte[i];
    fv[puncte[i].fi]--;
  }
  for (i = 0; i < m; i++) puncte[i] = cpyof_puncte[i];

  ///sort(queries, queries+4*n)
  fill(all(fv), 0);
  for (i = 0; i < 4*n; i++) fv[queries[i].fi.fi]++;
  for (i = 1; i <= maxh+1; i++) fv[i] += fv[i-1];
  for (i = 0; i < 4*n; i++) {
    cpyof_queries[fv[queries[i].fi.fi]-1] = queries[i];
    fv[queries[i].fi.fi]--;
  }
  for (i = 0; i < 4*n; i++) queries[i] = cpyof_queries[i];

  j = 0;
  int ans = 0;
  for (i = 0; i < 4*n; i++) {
    while (j < m && puncte[j].fi <= queries[i].fi.fi) {
      aib.upd(puncte[j].se, 1);
      j++;
    }

    if (queries[i].se) {
      ans += aib.qry(queries[i].fi.se);
    } else {
      ans -= aib.qry(queries[i].fi.se);
    }
  }

  fprintf(fout, "%d\n", ans);
  fclose(fout);

  return 0;
}