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#include<cstdio>
#include<iostream>
#include<algorithm>
#include<string>
#include<vector>
#include<cmath>
#include<queue>
#include<queue>
#include<stack>
#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include <chrono>

using namespace std;
using namespace __gnu_pbds;

typedef vector<int> VI;
typedef vector<VI> VVI;
typedef long long LL;
typedef unsigned long long ULL;
typedef long double LD;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<LL> VLL;
typedef vector<LD> VLD;
typedef vector<VLL > VVLL;
typedef vector<VLD > VVLD;
typedef vector<PII > VPII;
typedef vector<PLL > VPLL;
typedef __int128 int128;
template<class TIn>
using indexed_set = tree<
        TIn, null_type, less<TIn>,
        rb_tree_tag, tree_order_statistics_node_update>;
template<class T> using min_heap = priority_queue<T, vector<T>, greater<T>>;

#define FOR(x, b, e) for(int x=b; x<=(e); ++x)
#define FORD(x, b, e) for(int x=b; x>=(e); --x)
#define REP(x, n) for(int x=0; x<(n); ++x)
#define VAR(v, n) __typeof(n) v = (n)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(x) ((int)(x).size())
#define FOREACH(i, c) for(VAR(i, (c).begin()); i != (c).end(); ++i)
#define PB push_back
#define ST first
#define ND second
#define THIS (*this)
#define LSB(x) (x & -x)
#define SQR(x) ((x)*(x))

VI dx = {0, 1, 0, -1};
VI dy = {1, 0, -1, 0};
VI dxe = {-1, -1, 0, 1, 1, 1, 0, -1};
VI dye = {0, 1, 1, 1, 0, -1, -1, -1};

int n, m, k, q;
LL ans = 0;

bool exists(unordered_map<int, unordered_map<int, int> > &a, int x, int y) {
    return a[x].count(y);
}

int count(unordered_map<int, unordered_map<int, int> > &oa) {
    unordered_map<int, unordered_map<int, int> > a(oa);
    int ans = 0;
    bool inprogress = true;
    while (inprogress) {
        inprogress = false;
        for (auto ix = a.begin(); ix != a.end();) {
            for (auto iy = ix->ND.begin(); iy != ix->ND.end();) {
                int x = ix->ST, y = iy->ST;
                if ((!exists(a, x - 1, y) && !exists(a, x + 1, y)) || (!exists(a, x, y - 1) && !exists(a, x, y + 1))) {
                    ans++; inprogress = true; iy = ix->ND.erase(iy);
                    oa[x][y] = 1;
                } else iy++, oa[x][y] = 2;
            }
            if (ix->ND.empty()) ix = a.erase(ix);
            else ix++;
        }
    }
    return ans;
}

int status(unordered_map<int, unordered_map<int, int> > &a, int x, int y) {
    if (a[x].count(y)) return a[x][y];
    return 0; 
}

bool nontakeable(unordered_map<int, unordered_map<int, int> > &a, int x, int y) {
    return (status(a, x + 1, y) == 2 || status(a, x - 1, y) == 2) && (status(a, x, y + 1) == 2 || status(a, x, y - 1) == 2);
}

void add(unordered_map<int, unordered_map<int, int> > &a, int x, int y) {
    VI s(8); REP(j, 8) s[j] = status(a, x + dxe[j], y + dye[j]);
    queue<PII> q;
    for (int j = 0; j < 8; j += 2) {
        if (s[j] > 0 && s[j + 1] > 0 && s[(j + 2) % 8] > 0) {
            if (status(a, x + dxe[j], y + dye[j]) == 1) { a[x + dxe[j]][y + dye[j]] = 2; ans--; q.push({x + dxe[j], y + dye[j]}); }
            if (status(a, x + dxe[j + 1], y + dye[j + 1]) == 1) { a[x + dxe[j + 1]][y + dye[j + 1]] = 2; ans--; q.push({x + dxe[j + 1], y + dye[j + 1]}); }
            if (status(a, x + dxe[(j + 2) % 8], y + dye[(j + 2) % 8]) == 1) { a[x + dxe[(j + 2) % 8]][y + dye[(j + 2) % 8]] = 2; ans--; q.push({x + dxe[(j + 2) % 8], y + dye[(j + 2) % 8]}); }
        }
    }
    q.push({x, y});
    if (nontakeable(a, x, y)) {
        a[x][y] = 2;
    } else {
        a[x][y] = 1;
        ans++;
    }
    bool useBrute = false;
    while (!q.empty()) {
        auto [x, y] = q.front(); q.pop();
        REP(i, 4) {
            int xx = x + dx[i], yy = y + dy[i];
            if (status(a, xx + dx[i], yy + dy[i]) == 0 && (status(a, xx + dx[(i+1)%4], yy + dy[(i+1)%4]) > 0 || status(a, xx + dx[(i+3)%4], yy + dy[(i+3)%4]) > 0 )) {
                useBrute = true;
                while(!q.empty()) q.pop();
            } else if (status(a, xx, yy) == 1 && nontakeable(a, xx, yy)) {
                a[xx][yy] = 2;
                ans--;
                q.push({xx, yy});
            }
        }
    }
    if (useBrute) ans = count(a);
}

void remove(unordered_map<int, unordered_map<int, int> > &a, int x, int y) {
    int s = status(a, x, y);
    a[x].erase(y);
    if (s == 1) ans--;
    else {
        queue<PII> q;
        q.push({x, y});
        while (!q.empty()) {
            auto [x, y] = q.front(); q.pop();
            REP(i, 4) {
                int xx = x + dx[i], yy = y + dy[i];
                if (status(a, xx, yy) == 2 && !nontakeable(a, xx, yy)) {
                    a[xx][yy] = 1; ans++;
                    q.push({xx, yy});
                }
            }
        }
    }
}

int main() {
	ios_base::sync_with_stdio(0);
    cin.tie(NULL); cout.tie(NULL);
    cin >> n >> m >> k >> q;
    unordered_map<int, unordered_map<int, int> > a;
    REP(i, k) {
        int x, y; cin >> x >> y; --x; --y;
        a[x][y] = 1;
    }
    ans = count(a);
    cout << ans << '\n';
    REP(i, q) {
        int x, y; cin >> x >> y; --x; --y;
        if (status(a, x, y)) remove(a, x, y);
        else add(a, x, y);
        cout << ans << '\n';
    }

    return 0;
}