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#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int n, m, k, q;
map<pair<int,int>, int> mapa;
map<pair<int,int>, int> odw;
set<pair<int,int>> punkty;

vector<pair<int,int>> roza = {{-1, 0}, {0, 1}, {1, 0}, {0, -1}};

bool check(pair<int,int> u){
    if(u.first <= 0 or u.first > n or u.second <= 0 or u.second > m) return false;
    int l = mapa[{u.first, u.second - 1}];
    int lodw = odw[{u.first, u.second - 1}];
    int g = mapa[{u.first - 1, u.second}];
    int godw = odw[{u.first - 1, u.second}];
    int p = mapa[{u.first, u.second + 1}];
    int podw = odw[{u.first, u.second + 1}];
    int d = mapa[{u.first + 1, u.second}];
    int dodw = odw[{u.first + 1, u.second}];
    if(((l == 0 or lodw == 1) and (p == 0 or podw == 1)) or ((g == 0 or godw == 1) and (d == 0 or dodw == 1))) return true;
    return false;
}

void rozwiaz(){
    queue<pair<int,int>> q;
    ll w = 0;
    for(auto u : punkty){
        if(check(u)) {
            q.push(u);
            //cout << u.first << " " << u.second << " u\n";
        }
    }
    while(!q.empty()){
        auto e = q.front();
        q.pop();
        if(odw[e] == 1) continue;
        odw[e] = 1;
        w++;
        for(auto u : roza){
            pair<int,int> tmp = {e.first + u.first, e.second + u.second};
            if(odw[tmp] == 0 and mapa[tmp] == 1 and check(tmp)) q.push(tmp);
        }
    }
    odw.clear();
    cout << w << "\n";
    return;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> n >> m >> k >> q;
    int a, b;
    for(int i = 0; i < k; ++i){
        cin >> a >> b;
        mapa[{a,b}] = 1;
        punkty.insert({a,b});
    }
    rozwiaz();
    for(int i = 0; i < q; ++i){
        cin >> a >> b;
        mapa[{a,b}] = mapa[{a,b}] ^ 1;
        if(mapa[{a,b}] == 1){
            punkty.insert({a,b});
        }
        else{
            punkty.erase({a,b});
        }
        rozwiaz();
    }
    return 0;
}