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#include "bits/stdc++.h"

#define int long long
#define pi pair<long long, long long>
#define a3 array<long long, 3>

#define meow main

using namespace std;

signed meow() {
  cin.tie((ostream *)!ios::sync_with_stdio(false));

  int n, m, k, q;
  cin >> n >> m >> k >> q;
  set<pi> plansz;
  while (k--) {
    int x, y;
    cin >> x >> y;
    plansz.insert({x, y});
  }

  auto solve = [&]() {
    set<pair<int, pi>> hor;
    for (auto &[x, y] : plansz)
      hor.insert(
          {(int)(plansz.count({x, y - 1}) + plansz.count({x, y + 1})), {x, y}});
    set<pair<int, pi>> ver;
    for (auto &[x, y] : plansz)
      ver.insert(
          {(int)(plansz.count({x - 1, y}) + plansz.count({x + 1, y})), {x, y}});

    int res = 0;
    while (true) {
      if (hor.empty())
        break;
      auto [val, coords] = *hor.lower_bound({-1, {-1, -1}});
       bool brk = true;
      if (val == 0) {
        brk = false;
        hor.erase(hor.begin());
        ver.erase({0, coords});
        ver.erase({1, coords});
        ver.erase({2, coords});
        res++;
        if (ver.count({1, {coords.first + 1, coords.second}})) {
          ver.erase({1, {coords.first + 1, coords.second}});
          ver.insert({0, {coords.first + 1, coords.second}});
        }
        if (ver.count({2, {coords.first + 1, coords.second}})) {
          ver.erase({2, {coords.first + 1, coords.second}});
          ver.insert({1, {coords.first + 1, coords.second}});
        }
        if (ver.count({1, {coords.first - 1, coords.second}})) {
          ver.erase({1, {coords.first - 1, coords.second}});
          ver.insert({0, {coords.first - 1, coords.second}});
        }
        if (ver.count({2, {coords.first - 1, coords.second}})) {
          ver.erase({2, {coords.first - 1, coords.second}});
          ver.insert({1, {coords.first - 1, coords.second}});
        }
        continue;
      }
      if (hor.empty())
        break;
      auto [_val, _coords] = *ver.lower_bound({-1, {-1, -1}});
      if (_val == 0) {
        brk = false;
        ver.erase(ver.begin());
        hor.erase({0, _coords});
        hor.erase({1, _coords});
        hor.erase({2, _coords});
        res++;
        if (hor.count({1, {_coords.first, _coords.second + 1}})) {
          hor.erase({1, {_coords.first, _coords.second + 1}});
          hor.insert({0, {_coords.first, _coords.second + 1}});
        }
        if (hor.count({2, {_coords.first, _coords.second + 1}})) {
          hor.erase({2, {_coords.first, _coords.second + 1}});
          hor.insert({1, {_coords.first, _coords.second + 1}});
        }
        if (hor.count({1, {_coords.first, _coords.second - 1}})) {
          hor.erase({1, {_coords.first, _coords.second - 1}});
          hor.insert({0, {_coords.first, _coords.second - 1}});
        }
        if (hor.count({2, {_coords.first, _coords.second - 1}})) {
          hor.erase({2, {_coords.first, _coords.second - 1}});
          hor.insert({1, {_coords.first, _coords.second - 1}});
        }
      }

      if (brk)
        break;
    }

    return res;
  };

  cout << solve() << '\n';
  while (q--) {
    int x, y;
    cin >> x >> y;
    if (plansz.count({x, y}))
      plansz.erase({x, y});
    else
      plansz.insert({x, y});

    cout << solve() << '\n';
  }
  return 0;
}