monitor (nedovrseno)

//nedovrseno
#include <iostream>
#include <set>
#include <utility>

using namespace std;

int main() {
    int m, n, k, p; //redovi, koloni, dimenzija na slikata, broj na pikseli
    cin >> m >> n >> k >> p;

    set<pair<int,int>> rasipani;

    //int arr[m][n] = {};

    for (int i = 0; i < p; i++) {
        int x, y, tip;
        cin >> x >> y >> tip;

        if (tip == 1) {
            rasipani.insert({tip, x}); //tip=1, znaci horizontalna linija, znaci site pikseli na redot X se crni
            /*for (int b = 0; b < n; b++) {
               arr[x][b] = 1;
            }*/
        } else {
            rasipani.insert({tip, y}); //tip=2, znaci vertikalna linija, znaci site pikseli na kolonata Y se crni
            /*for (int a = 0; a < m; a++) {
               arr[a][y] = 2;
            }*/
        }
    }

    int best_cp = n * m;

    //cout << endl; ///IZBRISI IZBRISI IZBRISI

    for (int x = 0; x < m; x++) {
        for (int y = 0; y < n; y++) {

            int crni_pikseli = 0;

            for (int a = 0; a < k; a++) {
                if (rasipani.find({1, x + a}) != rasipani.end()) {
                    crni_pikseli += k;
                }
            }
            for (int b = 0; b < k; b++) {
                if (rasipani.find({2, y + b}) != rasipani.end()) {
                    crni_pikseli += k;
                }
            }

            if (crni_pikseli < best_cp) {
                best_cp = crni_pikseli;
            }
/*
            int temp[k][k] = {};

            for (int a = 0; a < k; a++) {
                for (int b = 0; b < k; b++) {
                    temp[a][b] = arr[a + x][b + y];
                    arr[a + x][b + y] = 3;
                }
            }

            for (int a = 0; a < m; a++) {
                for (int b = 0; b < n; b++) {
                    cout << arr[a][b] << " ";
                }
                cout << endl;
            }

            cout << "cp: " << crni_pikseli << endl << endl;

            for (int a = 0; a < k; a++) {
                for (int b = 0; b < k; b++) {
                    arr[a + x][b + y] = temp[a][b];
                }
            }*/
        }
    }

    cout << best_cp << endl;
/*
    for (int a = m; a < m; a++) {
        for (int b = 0; b < n; b++) {
            cout << arr[a][b] << " ";
        }
        cout << endl;
    }
*/
    return 0;
}