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#include <bits/stdc++.h>
#define f first
#define s second
using namespace std;

struct edg {
    long long wx, wy;
    bool jdr;
};

long long kod(long long wx, long long wy) {
    return (wx << 20) | wy;
}

unordered_map<long long, edg> wez;

long long lca = 0;
long long ljd = 0;

void prz(long long poc, unordered_set<long long> &odw) {
    vector<long long> skl;
    queue<long long> q;
    q.push(poc);
    odw.insert(poc);

    while (!q.empty()) {
        //cout << "IT";
        long long upd = q.front();
        //cout << upd << '\n';
        q.pop();
        skl.push_back(upd);
        auto it = wez.find(upd);
        if (it == wez.end()) continue;

        long long wx = (*it).s.wx;
        long long wy = (*it).s.wy;

        //cout << wx << ' ' << wy << '\n';

        long long dx[4] = { -1, 1, 0, 0};
        long long dy[4] = {0, 0, -1, 1};

        for (long long i = 0; i < 4; i++) {
            long long nx = wx + dx[i];
            long long ny = wy + dy[i];
            //cout << nx << ' ' << ny << '\n';
            long long kl = kod(nx, ny);
            if (wez.find(kl) != wez.end()) {
                if (odw.find(kl) == odw.end()) {
                    odw.insert(kl);
                    q.push(kl);
                }
            }
        }
    }

    long long roz = skl.size();
    unordered_map<long long, long long> ind(roz * 2);

    for (long long i = 0; i < roz; i++) ind[skl[i]] = i;

    vector<long long> hde(roz, 0), vde(roz, 0);
    vector<bool> skj(roz, 1);

    for (long long i = 0; i < roz; i++) {
        long long kl = skl[i];
        edg nd = wez[kl];

        long long wx = nd.wx;
        long long wy = nd.wy;

        long long kll = kod(wx, wy - 1);
        long long klr = kod(wx, wy + 1);
        //cout << kll << ' ' << klr << '\n';
        if (ind.find(kll) != ind.end()) hde[i]++;
        if (ind.find(klr) != ind.end()) hde[i]++;

        long long klu = kod(wx - 1, wy);
        long long  kld = kod(wx + 1, wy);
        //cout << klu << ' ' << kld << '\n';
        if (ind.find(klu) != ind.end()) vde[i]++;
        if (ind.find(kld) != ind.end()) vde[i]++;
    }

    queue<long long> odl;
    for (long long i = 0; i < roz; i++) {
        if (hde[i] < 1 or vde[i] < 1) {
            //cout << "CHUJ1";
            odl.push(i);
            skj[i] = 0;
        }
    }
    while (!odl.empty()) {
        long long i = odl.front();
        odl.pop();
        long long kl = skl[i];
        edg nd = wez[kl];
        long long wx = nd.wx;
        long long wy = nd.wy;
        long long dx[4] = { -1, 1, 0, 0};
        long long dy[4] = {0, 0, -1, 1};

        for (long long d = 0; d < 4; d++) {
            long long nx = wx + dx[d], ny = wy + dy[d];
            long long nkl = kod(nx, ny);
            if (ind.find(nkl) == ind.end()) continue;

            long long j = ind[nkl];

            if (!skj[j]) continue;

            if (nx == wx) hde[j]--;

            if (ny == wy) vde[j]--;

            if (skj[j] and (hde[j] < 1 or vde[j] < 1)) {
                //cout << "CHUJ2";
                skj[j] = 0;
                odl.push(j);
                //cout << j << '\n';
            }
        }
    }

    for (long long i = 0; i < roz; i++) {
        long long kl = skl[i];
        bool stv = wez[kl].jdr;
        //cout << kl << ' ' << stv << '\n';
        if (stv and !skj[i]) ljd--;
        else if (!stv and skj[i]) ljd++;
        //cout << ljd << ' ' << skj[i] << '\n';
        wez[kl].jdr = skj[i];
    }
}

void upd(vector<long long> &nas) {
    unordered_set<long long> odw;
    for (auto kl : nas) {
        if (wez.find(kl) == wez.end()) continue;
        if (odw.find(kl) != odw.end()) continue;
        prz(kl, odw);
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);

    long long n, m, k, q;
    cin >> n >> m >> k >> q;
    for (long long i = 0; i < k; i++) {
        long long wx, wy;
        cin >> wx >> wy;
        long long kl = kod(wx, wy);
        //cout << kl << '\n';
        wez[kl] = {wx, wy, 0};
        lca++;
    }

    unordered_set<long long> odw;

    for (auto &p : wez) {
        long long kl = p.f;
        if (odw.find(kl) == odw.end()) prz(kl, odw);
    }

    cout << (lca - ljd) << "\n";

    for (long long i = 0; i < q; i++) {
        long long wx, wy;
        cin >> wx >> wy;
        long long kl = kod(wx, wy);
        //cout <<"KL"<< kl << '\n';
        vector<long long> nas;

        if (wez.find(kl) != wez.end()) {
            //cout << "CHUJ3" << '\n';
            long long dx[4] = { -1, 1, 0, 0};
            long long dy[4] = {0, 0, -1, 1};
            for (long long d = 0; d < 4; d++) {
                long long nx = wx + dx[d];
                long long ny = wy + dy[d];
                //cout << nx << ' ' << ny << '\n';
                long long nkl = kod(nx, ny);
                if (wez.find(nkl) != wez.end()) nas.push_back(nkl);
                //cout << "NKL: "<< nkl << '\n';
            }

            if (wez[kl].jdr) ljd--;
            //cout << ljd << '\n';
            wez.erase(kl);
            lca--;
            //cout << lca << '\n';
        }
        else {
            wez[kl] = {wx, wy, 0};
            lca++;
            //cout << lca << '\n';
            nas.push_back(kl);
        }

        upd(nas);
        // for(auto i : nas) cout << i << ' ';
        // cout << '\n';
        cout << (lca - ljd) << "\n";
    }
}