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#include <iostream>
#include <algorithm>
#include <vector>
#include <math.h>
#include <set>

using namespace std;

typedef long long ll;

set<pair<int, int>> mp;
set<pair<int, int>> blocked;

void check_and_mark(pair<int, int> pos) {    
    if (mp.count(pos) &&
        mp.count({pos.first - 1, pos.second}) && 
        mp.count({pos.first,     pos.second - 1}) &&
        mp.count({pos.first - 1, pos.second - 1})) {
            blocked.insert(pos);
            blocked.insert({pos.first - 1, pos.second});
            blocked.insert({pos.first,     pos.second - 1});
            blocked.insert({pos.first - 1, pos.second - 1});
        }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int  n, m, k, q;
    cin >> n >> m >> k >> q;
    vector<pair<int,int>> pos(k);
    for (int i = 0; i < k; i++) {
        cin >> pos[i].first >> pos[i].second;
        mp.insert(pos[i]);
    }
    for (int i = 0; i < k; i++) {
        check_and_mark(pos[i]);
    }

    cout << mp.size() - blocked.size() << "\n";
    for (int i = 0; i < q; i++) {
        int x0, y0;
        cin >> x0 >> y0;
        if (mp.count({x0, y0})) {
            mp.erase({x0, y0});
        } else {
            mp.insert({x0, y0});
        }
        for (int x = x0 - 1; x <= x0 + 1; x++) {
            for (int y = y0 - 1; y <= y0 + 1; y++) {
                blocked.erase({x, y});
            }
        }
        for (int x = x0 - 1; x <= x0 + 1; x++) {
            for (int y = y0 - 1; y <= y0 + 1; y++) {
                check_and_mark({x, y});
            }
        }
/*        for (int i = 1; i < 10; i++) {
            for (int j = 1; j < 10; j++) {
                cout << (mp.count({i, j}) ? "#" : "."); 
            }
            cout << "\n";
        }
        cout << "---\n";
        for (int i = 1; i < 10; i++) {
            for (int j = 1; j < 10; j++) {
                cout << (blocked.count({i, j}) ? "#" : "."); 
            }
            cout << "\n";
        }*/
        cout << mp.size() - blocked.size() << "\n";
    }
    return 0;
}