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#include <iostream>
#include <queue>
#include <unordered_set>

using namespace std;

using Brick = pair<long long, long long>;

struct BrickHash {
    std::size_t operator()(const Brick &k) const {
        return hash<long long>()(k.first ^ k.second << 32);
    }
};

using BrickSet = unordered_set<Brick, BrickHash>;

Brick left(Brick brick) {
    return {brick.first, brick.second - 1};
}

Brick right(Brick brick) {
    return {brick.first, brick.second + 1};
}

Brick up(Brick brick) {
    return {brick.first - 1, brick.second};
}

Brick down(Brick brick) {
    return {brick.first + 1, brick.second};
}


bool present(Brick brick, const BrickSet &bricks, const BrickSet &removed) {
    return !removed.contains(brick) && bricks.contains(brick);
}

bool canRemove(Brick brick, const BrickSet &bricks, const BrickSet &removed) {
    return (!present(left(brick), bricks, removed) && !present(right(brick), bricks, removed)) || (!present(up(brick), bricks, removed) && !present(down(brick), bricks, removed));
}

BrickSet removed;

void printRemoved() {
    for (auto [a, b] : removed) {
        cout << "(" << a << ", " << b << ") ";
    }
    cout << "\n";
}

void addNeighborsToQueue(const BrickSet &bricks, const BrickSet &removed, Brick brick, queue<Brick> &bfs) {
    if (present(left(brick), bricks, removed)) {
        bfs.push(left(brick));
    }
    if (present(right(brick), bricks, removed)) {
        bfs.push(right(brick));
    }
    if (present(up(brick), bricks, removed)) {
        bfs.push(up(brick));
    }
    if (present(down(brick), bricks, removed)) {
        bfs.push(down(brick));
    }
}

int solve(const BrickSet &bricks, bool useStartBricks = false, BrickSet startBricks = {}) {
    queue<Brick> bfs;
    if (useStartBricks) {
        for (auto brick : startBricks) {
            bfs.push(brick);
        }
    } else {
        for (auto brick : bricks) {
            bfs.push(brick);
        }
    }
    while (!bfs.empty()) {
        auto brick = bfs.front();
        bfs.pop();
        if (canRemove(brick, bricks, removed)) {
            removed.insert(brick);
            addNeighborsToQueue(bricks, removed, brick, bfs);
        }
    }
    return size(removed);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m, k, q;
    cin >> n >> m >> k >> q;
    BrickSet bricks;
    for (int i = 0; i < k; ++i) {
        int x, y;
        cin >> x >> y;
        bricks.insert({x, y});
    }
    cout << solve(bricks) << '\n';
    for (int i = 0; i < q; ++i) {
        Brick newBrick;
        cin >> newBrick.first >> newBrick.second;
        if (bricks.contains(newBrick)) {
            bricks.erase(newBrick);
            removed.erase(newBrick);
            if (removed.contains(newBrick)) {
                cout << size(removed) << '\n';
            } else {
                BrickSet startBricks;
                if (present(left(newBrick), bricks, removed) && canRemove(left(newBrick), bricks, removed)) {
                    startBricks.insert(left(newBrick));
                }
                if (present(right(newBrick), bricks, removed) && canRemove(right(newBrick), bricks, removed)) {
                    startBricks.insert(right(newBrick));
                }
                if (present(up(newBrick), bricks, removed) && canRemove(up(newBrick), bricks, removed)) {
                    startBricks.insert(up(newBrick));
                }
                if (present(down(newBrick), bricks, removed) && canRemove(down(newBrick), bricks, removed)) {
                    startBricks.insert(down(newBrick));
                }
                cout << solve(bricks, true, startBricks) << '\n';
            }
        } else {
            bricks.insert(newBrick);
            if (canRemove(newBrick, bricks, {})) {
                removed.insert(newBrick);
                cout << size(removed) << "\n";
            } else {
                BrickSet startBricks;
                queue<Brick> tmp;
                tmp.push(newBrick);
                while (!tmp.empty()) {
                    auto brick = tmp.front();
                    tmp.pop();
                    if (!canRemove(brick, bricks, {})) {
                        removed.erase(brick);
                        startBricks.insert(brick);
                        if (present(left(brick), removed, {})) {
                            tmp.push(left(brick));
                        }
                        if (present(right(brick), removed, {})) {
                            tmp.push(right(brick));
                        }
                        if (present(up(brick), removed, {})) {
                            tmp.push(up(brick));
                        }
                        if (present(down(brick), removed, {})) {
                            tmp.push(down(brick));
                        }
                    }
                }
                cout << solve(bricks, true, startBricks) << '\n';
            }
        }
    }
}