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#include <iostream>
#include <vector>
#include <queue>
using namespace std;

vector<vector<bool>> plansz ={};
queue<pair<int,int>> pionki = {};
int  n, m, k, q ;

void print_v(vector<vector<bool>> const &plansz) { 
	for (auto w: plansz) {
		for (auto p: w) {
			if (p)
				cout << "#";
			else
				cout << " ";
		}
		cout << endl;
	}
}

bool test_w(int x, int y, vector<vector<bool>> const &plansz) {
	return( (!plansz[x-1][y] && !plansz[x+1][y]) || (!plansz[x][y-1] && !plansz[x][y+1]) );
}

int licz_z(vector<vector<bool>> plansz, queue<pair<int,int>> pionki) {
	int zdjetych = 0;
	pair<int,int> p; 
	while (!pionki.empty()) {
        p = pionki.front();
		if (plansz[p.first][p.second]) {
			if (test_w(p.first, p.second, plansz)) {
				zdjetych++;
				plansz[p.first][p.second] = false;
				if (p.first>0) pionki.push({p.first-1,p.second});
				if (p.first<n) pionki.push({p.first+1,p.second});
				if (p.second>0) pionki.push({p.first,p.second-1});
				if (p.second<m) pionki.push({p.first,p.second+1});
			}
		}
        pionki.pop();
    }
	// print_v(plansz);
	return (zdjetych);
}

int main()
{
    ios_base::sync_with_stdio(0);
    cout.tie(0);
    cin.tie(0);
	int x,y;
	cin >>  n >> m >> k >> q;
	for (int i=0; i <= n+1; i++) {
		plansz.push_back({});
		for (int j=0; j<=m+1; j++) {
			plansz[i].push_back(false);
		}
	}

	for (int j=0; j<k; j++) {
		cin >> x >> y;
		plansz[x][y]=true;
		pionki.push({x,y});
	}
	// print_v(plansz);
	cout << licz_z(plansz, pionki) << endl;
	for (int i=0; i<q; i++) {
		cin >> x >> y;
		plansz[x][y]=!plansz[x][y];
		pionki.push({x,y});
		// print_v(plansz);
		cout << licz_z(plansz, pionki) << endl;
	}
	return(0);
}