10分求助！

#include <iostream>
using namespace std;
int main() {
	int op;
	long long n,m,q,k,x,count=0,l[200001]={0},s[200001]={0};
	cin >> n >> m >> q >> k;
	for (long long a = 0; a < q; a++) {
		cin >> op >> x;
		if (op == 1)
			++l[x];
		else
			++s[x];
	}
	for (long long i = 1; i <= n; i++)
		for (long long j = 1; j <= m; j++){
			if (l[i]+s[j] == k)
				count++;
            if(l[i]+s[j]==0)
                count++;
		}
	cout << n*m-count;
	return 0;
}