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#include <bits/stdc++.h>

using namespace std;

int res(vector<vector<bool>> t, int n, int m){
	
	bool tak = 1;
	int ret = 0;
	while(tak){
		tak = 0;
		for(int i = 1; i <= n; ++i){
			for(int j = 1; j <= m; ++j){
				if(!t[i][j]) continue;
				if(!t[i - 1][j] && !t[i + 1][j]){
					t[i][j] = 0; tak = 1;
					ret++;
				}
				else if(!t[i][j - 1] && !t[i][j + 1]){
					t[i][j] = 0; tak = 1;
					ret++;
				}
			}
		}
	}
	return ret;
}
int main(){
	
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	
	int n, m;
	cin >> n >> m;
	
	int k, q; 
	cin >> k >> q;
	
	vector<vector<bool>> v(n + 2);
	for(int i = 0; i <= n + 1; ++i) v[i].resize(m + 2, false);
	
	int x, y;
	for(int i = 0; i < k; ++i){
		cin >> x >> y;
		v[x][y] = 1;
	}
	
	cout << res(v, n, m) << "\n";
	for(int i = 0; i < q; ++i){
		cin >> x >> y;
		if(v[x][y]) v[x][y] = 0;
		else v[x][y] = 1;
		cout << res(v, n, m) << "\n";
	}
	
	return 0;
}