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

int n, m, k, q;

bool is_removable(set<pair<int, int>> &b, int x, int y) {
    bool h = ((y == 1) || (b.find({x, y - 1}) == b.end())) &&
             ((y == m) || (b.find({x, y + 1}) == b.end()));

    bool v = ((x == 1) || (b.find({x - 1, y}) == b.end())) &&
             ((x == n) || (b.find({x + 1, y}) == b.end()));

    return h || v;
}


int remove(set<pair<int, int>> &blocks) {
    queue<pair<int ,int>> q;
    int cnt = 0;

    set<pair<int, int>> temp = blocks;

    for(const auto &[x, y] : temp) {
        if(is_removable(temp, x, y))
        q.push({x, y});
    }

    while(!q.empty()) {
        auto b = q.front();
        q.pop();

        if(temp.find(b) == temp.end()) {
            continue;
        }

        temp.erase(b);
        cnt++;

        vector<pair<int, int>> neighbours = {
            {b.first - 1, b.second}, {b.first + 1, b.second},
            {b.first, b.second - 1}, {b.first, b.second + 1}
        };

        for(const auto &[x, y] : neighbours) {
            if(temp.find({x, y}) != temp.end() && is_removable(temp, x, y)) {
                q.push({x, y});
            }
        }
    }

    return cnt;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    cin >> n >> m >> k >> q;
    set<pair<int, int>> blocks;

    for(int i = 0; i < k; i++) {
        int x, y;
        cin >> x >> y;

        blocks.insert({x, y});
    }

    int removed = remove(blocks);

    cout << removed << '\n';

    for(int i = 0; i < q; i++) {
        int x, y;
        cin >> x >> y;

        if(blocks.find({x, y}) == blocks.end()) {
            blocks.insert({x, y});
        } else {
            blocks.erase({x, y});
        }

        removed = remove(blocks);

        cout << removed << '\n';
    }

}