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#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
using namespace __gnu_pbds;
using namespace std;
#define pb push_back
#define st first
#define nd second
typedef long long ll;
typedef long double ld;
const ll I = 1000'000'000'000'000'000LL;
const int II = 2'000'000'000;
const ll M = 1000'000'007LL;
const int N = 275'007;
pair<int, int> tab[N];
int l[N], r[N], g[N], d[N];

int czy[N], kw[N], prs[N];
int answer = 0;

map<pair<int, int>, int> pos;
int cur[30][30];

inline int Get(int i, int j)
{
    if(i <= 0 || j <= 0) return 0;
    if(pos.find(make_pair(i, j)) == pos.end()) return 0;
    return pos[make_pair(i, j)];
}

bool Check(int a)
{
    bool cr = ((czy[l[a]] & czy[r[a]]) | (czy[g[a]] & czy[d[a]]));
    //cout << "C: " << a << " | " << cr << " ? " << czy[a] << " " << czy[0] << "\n";
    if(cr == czy[a])
        return 0;
    answer -= (int)czy[a];
    czy[a] = cr;
    answer += czy[a];
    return 1;
}

void Upd(int v)
{
    if(l[v] > 0 && Check(l[v]))
        Upd(l[v]);
    if(r[v] > 0 && Check(r[v]))
        Upd(r[v]);
    if(g[v] > 0 && Check(g[v]))
        Upd(g[v]);
    if(d[v] > 0 && Check(d[v]))
        Upd(d[v]);
}

void ReCalc(int a, int b, int l)
{
    for(int i = 1; i <= l; ++i)
    {
        answer -= (int)czy[i];
        czy[i] = 0;
    }
    for(int i = 1; i <= l; ++i)
        if(prs[i] && Check(i))
            Upd(i);
}

void Solve()
{
    int h, w, n, q;
    cin >> h >> w >> n >> q;
    czy[0] = 1;
    for(int i = 1; i <= n; ++i)
    {
        cin >> tab[i].st >> tab[i].nd;
        pos[tab[i]] = i;
    }
    for(int i = 1; i <= n; ++i)
    {
        l[i] = Get(tab[i].st, tab[i].nd - 1);
        r[i] = Get(tab[i].st, tab[i].nd + 1);
        g[i] = Get(tab[i].st - 1, tab[i].nd);
        d[i] = Get(tab[i].st + 1, tab[i].nd);
        prs[i] = 1;
        //cout << i << " " << "E: " << l[i] << " " << g[i] << " " << r[i] << " " << d[i] << "\n";
    }
    for(int i = 1; i <= n; ++i)
        if(Check(i))
            Upd(i);
    cout << answer << "\n";
    int cnt = n;
    for(int i = 1; i <= q; ++i)
    {
        int a, b;
        cin >> a >> b;
        if(pos.find(make_pair(a, b)) == pos.end())
        {
            ++cnt;
            int x = cnt;
            pos[make_pair(a, b)] = x;
            l[x] = Get(a, b - 1);
            r[x] = Get(a, b + 1);
            g[x] = Get(a - 1, b);
            d[x] = Get(a + 1, b);
            r[l[x]] = x; l[r[x]] = x;
            g[d[x]] = x; d[g[x]] = x;
            prs[x] = 1;
        }else
        {
            int x = pos[make_pair(a, b)];
            prs[x] = 0;
            r[l[x]] = 0; l[r[x]] = 0;
            g[d[x]] = 0; d[g[x]] = 0;
            pos.erase(make_pair(a, b));
        }
        ReCalc(a, b, cnt);
        cout << answer << "\n";
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    //int t; cin >> t;
    //while(t--)
        Solve();

    return 0;
}