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#include <iostream>
#include <set>
#include <vector>
using namespace std;

struct Board {
    int n, m;
    set<pair<int, int>> blocks;

    Board(int n, int m) : n(n), m(m) {}

    bool isRemovable(int x, int y, const set<pair<int, int>>& currentBlocks) {
        bool left = (currentBlocks.count({x, y - 1}) == 0);
        bool right = (currentBlocks.count({x, y + 1}) == 0);
        bool up = (currentBlocks.count({x - 1, y}) == 0);
        bool down = (currentBlocks.count({x + 1, y}) == 0);
        return (left && right) || (up && down);
    }

    int countMaxRemovable() {
        set<pair<int, int>> currentBlocks = blocks;
        set<pair<int, int>> removable;
        for (auto [x, y] : currentBlocks) {
            if (isRemovable(x, y, currentBlocks)) {
                removable.insert({x, y});
            }
        }

        int count = 0;
        while (!removable.empty()) {
            auto it = removable.begin();
            int x = it->first, y = it->second;
            removable.erase(it);
            currentBlocks.erase({x, y});
            count++;
            
            for (int dx = -1; dx <= 1; dx++) {
                for (int dy = -1; dy <= 1; dy++) {
                    if (dx * dy == 0 && dx != dy) {
                        int nx = x + dx, ny = y + dy;
                        if (currentBlocks.count({nx, ny}) && isRemovable(nx, ny, currentBlocks)) {
                            removable.insert({nx, ny});
                        }
                    }
                }
            }
        }
        return count;
    }

    void add(int x, int y) {
        blocks.insert({x, y});
    }

    void remove(int x, int y) {
        blocks.erase({x, y});
    }
};

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

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

    Board board(n, m);

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

    cout << board.countMaxRemovable() << "\n";

    for (int i = 0; i < q; i++) {
        int x, y;
        cin >> x >> y;
        if (board.blocks.count({x, y})) {
            board.remove(x, y);
        } else {
            board.add(x, y);
        }
        cout << board.countMaxRemovable() << "\n";
    }

    return 0;
}