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#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
#define mp(x, y) make_pair(x, y)

int n, m, k, q;
set<pair<int, int>> GRID;

int answer()
{
	set<pair<int, int>> grid = GRID;
	auto exists = [&](int x, int y){
		return (grid.find(mp(x, y)) != grid.end());
	};
	deque<pair<int, int>> dq;
	for (auto &[x, y] : GRID)
	{
		if ( (!exists(x-1, y) && !exists(x+1, y)) || (!exists(x, y-1) && !exists(x, y+1)) )
		{
			grid.erase(mp(x, y));
			dq.push_back(make_pair(x, y));
		}
	}
	int ans = 0;
	while (dq.size())
	{
		auto [x0, y0] = dq.front();
		dq.pop_front();
		ans++;
		for (int x = max(x0-1, 0); x <= min(x0+1, n-1); x++)
		{
			for (int y = max(y0-1, 0); y <= min(y0+1, m-1); y++)
			{
				if (!exists(x, y))
					continue;
				if ( (!exists(x-1, y) && !exists(x+1, y)) || (!exists(x, y-1) && !exists(x, y+1)) )
				{
					grid.erase(mp(x, y));
					dq.push_back(make_pair(x, y));
				}
			}
		}
	}
	return ans;
}

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

	cin >> n >> m >> k >> q;
	for (int i = 0; i < k; i++)
	{
		int x, y;
		cin >> x >> y;
		x--; y--;
		GRID.insert(mp(x, y));
	}
	cout << answer() << "\n";
	for (int i = 0; i < q; i++)
	{
		int x, y;
		cin >> x >> y;
		x--; y--;
		if (GRID.find(mp(x, y)) == GRID.end())
			GRID.insert(mp(x, y));
		else
			GRID.erase(mp(x, y));
		cout << answer() << "\n";
	}
}