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#include<iostream>
#include<iomanip>
#include<vector>
#include<map>
#include<algorithm>

#define REP(i,n) for(int i=0;i<(n);++i)
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)

using namespace std;

typedef long long int llint;

const int MAX_N = 200000, MAX_V=150000;

int xx[1+MAX_V], yy[1+MAX_V], qx[1+MAX_V], qy[1+MAX_V];

int vn[1+MAX_V], vs[1+MAX_V], ve[1+MAX_V], vw[1+MAX_V];

map<pair<int,int>, int> vmap;

int n, m, k, q, num_z;

int z[1+MAX_V];

void sprawdz(int i) {
	//cout << "SPRAWDZ i=" << i << " x="<<xx[i] << " y="<<yy[i] << " z=" << z[i] << endl;
	if (z[i]) return;
	if (z[vn[i]] && z[vs[i]]) {
		//cout << "SPRAWDZ i=" << i << " z:=1 (NS)" << endl;
		z[i] = 1;
		num_z++;
		sprawdz(ve[i]);
		sprawdz(vw[i]);
	} else if (z[ve[i]] && z[vw[i]]) {
		//cout << "SPRAWDZ i=" << i << " z:=1 (EW)" << endl;
		z[i] = 1;
		num_z++;
		sprawdz(vn[i]);
		sprawdz(vs[i]);
	}
}

void blokuj_somsiadow(int i);

vector<int> blocked;

inline void blokuj_somsiada(int j) {
	//cout << "BLOKUJ j="<<j<< " z="<<z[j]<<endl;
	if (z[j]) {
		z[j] = 0;
		num_z--;
		blocked.push_back(j);
		blokuj_somsiadow(j);
	}
}

void blokuj_somsiadow(int i) {
	//cout << "SASIAD i="<<i << endl;
	if (vn[i]) blokuj_somsiada(vn[i]);
	if (vs[i]) blokuj_somsiada(vs[i]);
	if (ve[i]) blokuj_somsiada(ve[i]);
	if (vw[i]) blokuj_somsiada(vw[i]);
}

void sprawdz_somsiadow(int i) {
	blocked.clear();
	blokuj_somsiadow(i);
	int mbs = blocked.size();
	REP(ix, mbs) sprawdz(blocked[ix]);
	sprawdz(i);
}

void update_compass(int i) {
	int x = xx[i], y = yy[i];	
	auto it = vmap.find(make_pair(x+1, y));
	if (it != vmap.end() && it->second ) { ve[i] = it->second; vw[ve[i]] = i; } else { ve[i] = 0; }
	it = vmap.find(make_pair(x-1, y));
	if (it != vmap.end() && it->second) { vw[i] = it->second; ve[vw[i]] = i; } else { vw[i] = 0; }
	it = vmap.find(make_pair(x, y+1));
	if (it != vmap.end() && it->second) { vs[i] = it->second; vn[vs[i]] = i; } else { vs[i] = 0; }
	it = vmap.find(make_pair(x, y-1));
	if (it != vmap.end() && it->second) { vn[i] = it->second; vs[vn[i]] = i; } else { vn[i] = 0; }
}

int main(void) {	
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	cin >> n >> m >> k >> q;
	FOR(i, 1, k) cin >> xx[i] >> yy[i];
	FOR(j, 1, q) cin >> qx[j] >> qy[j];

	FOR(i, 1, k) vmap[make_pair(xx[i], yy[i])] = i;
	FOR(i, 0, k) vn[i]=vs[i]=ve[i]=vw[i]=0;	
	FOR(i, 1, k) update_compass(i);
	
	{
		FOR(i, 1, k) z[i] = 0;
		z[0] = 1;
		FOR(i, 1, k) sprawdz(i);
		cout << num_z << endl;
	}
	
	FOR(j, 1, q) {
		auto it = vmap.find(make_pair(qx[j], qy[j]));
		if (it == vmap.end() || !it->second) {
			k++; xx[k] = qx[j]; yy[k] = qy[j];
			//cout << "INSERT k=" <<k << " x=" << xx[k] << " y=" << yy[k] << endl;
			vmap[make_pair(xx[k], yy[k])] = k;
			update_compass(k);
			// cout << "KLOCEK #" << k <<" (" << xx[k] << ","<< yy[k] << ") N:" 
			//	 << vn[k] << " E:" << ve[k] << " S:" << vs[k] << " W:" << vw[k] << endl;
			z[k] = 0;
			sprawdz_somsiadow(k);
		} else {
			int i = it->second;
			if (z[i]) {
				//cout << "REMOVE z:=0 i=" << i << endl;
				z[i] = 0;
				num_z--;
			}
			if (i < k) {
				//cout << "REMOVE i=" <<i << " k=" << k << " x=" << xx[i] << " y=" << yy[i] << endl;
				vmap[make_pair(xx[i], yy[i])] = 0;
				vmap[make_pair(xx[k], yy[k])] = i;
				z[i] = z[k];
				int ix_ve = ve[i], ix_vw = vw[i], ix_vn = vn[i], ix_vs = vs[i];
				vw[ve[i]] = ve[vw[i]] = vn[vs[i]] = vs[vn[i]] = 0;
				if (ve[k]) vw[ve[k]] = i;
				if (vw[k]) ve[vw[k]] = i;
				if (vs[k]) vn[vs[k]] = i;
				if (vn[k]) vs[vn[k]] = i;
				xx[i] = xx[k]; yy[i] = yy[k]; k--;
				update_compass(i);
				sprawdz(ix_ve == k+1 ? i : ix_ve);
				sprawdz(ix_vw == k+1 ? i : ix_vw);
				sprawdz(ix_vn == k+1 ? i : ix_vn);
				sprawdz(ix_vs == k+1 ? i : ix_vs);
			} else {
				//cout << "ERASE i=" <<i << " x=" << xx[i] << " y=" << yy[i] << endl;
				vmap.erase(it);
				int ix_ve = ve[i], ix_vw = vw[i], ix_vn = vn[i], ix_vs = vs[i];
				vw[ve[i]] = ve[vw[i]] = vn[vs[i]] = vs[vn[i]] = 0;				
				k--;
				sprawdz(ix_ve);
				sprawdz(ix_vw);
				sprawdz(ix_vn);
				sprawdz(ix_vs);
			}
		}

		cout << num_z << endl;
	}
		
	return 0;
}