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#include <bits/stdc++.h>
#define pb push_back
#define f first
#define s second
#define ll long long
#define dbg(x) cerr << #x << ": " << x << "\n"
#define mp make_pair

using namespace std;

const int N = 500005;
map<pair<int, int>, bool> M;
map<pair<int, int>, bool> vis;
vector<pair<int, int>> neigh = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};

bool check(int x, int y)
{
    if (!M[{x, y}] || vis[{x, y}])
        return false;
    bool is_left = (M[{x - 1, y}] && vis[{x - 1, y}] == false);
    bool is_right = (M[{x + 1, y}] && vis[{x + 1, y}] == false);
    bool is_down = (M[{x, y - 1}] && vis[{x, y - 1}] == false);
    bool is_up = (M[{x, y + 1}] && vis[{x, y + 1}] == false);
    return ((!is_left && !is_right) || (!is_down && !is_up));
}

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

    int n, m, k, q;
    cin >> n >> m >> k >> q;

    set<pair<int, int>> blocks;

    for (int i = 1; i <= k; i++)
    {
        int x, y;
        cin >> x >> y;
        blocks.insert({x, y});
        M[{x, y}] = true;
    }

    queue<pair<int, int>> Q;
    for (int i = 1; i <= q + 1; i++)
    {
        for (auto it = blocks.begin(); it != blocks.end(); it++)
        {
            int x = (*it).f;
            int y = (*it).s;
            vis[{x, y}] = false;
            if ((!M[{x - 1, y}] && !M[{x + 1, y}]) || (!M[{x, y - 1}] && !M[{x, y + 1}]))
            {
                vis[{x, y}] = true;
                Q.push({x, y});
            }
        }
        int res = 0;
        while (!Q.empty())
        {
            res++;
            auto [x, y] = Q.front();
            Q.pop();
            for (auto [x1, y1] : neigh)
            {
                if (check(x + x1, y + y1))
                {
                    vis[{x + x1, y + y1}] = true;
                    Q.push({x + x1, y + y1});
                }
            }
        }
        cout << res << "\n";
        if (i == q + 1)
            continue;
        int x, y;
        cin >> x >> y;
        if (M[{x, y}])
            blocks.erase({x, y});
        else
            blocks.insert({x, y});
        M[{x, y}] = !M[{x, y}];
    }

    return 0;
}