#include "bits/stdc++.h"

using namespace std;

using ll = long long;
using ld = long double;

const double PI = 3.1415926535897932384626433832795;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { -1, 0, 1, 0 };

int gcd(int x, int y) { return y ? gcd(y, x % y) : abs(x); }
ll gcd(ll x, ll y) { return y ? gcd(y, x % y) : abs(x); }
int lcm(int x, int y) { return x / gcd(x, y) * y; }
ll lcm(ll x, ll y) { return x / gcd(x, y) * y; }

int h, w, k, p;
vector<int> x, y;
vector<string> name;

ll f(int mask) {
	vector<int> friends;
	for (int i = 0; i < k; i++) {
		if (mask & (1 << i)) {
			friends.push_back(i);
		}
	}

	if (friends.size() != p) {
		return -1LL;
	}

	vector<vector<bool>> isMove(w + 1, vector<bool>(h + 1, true));
	for (int i = 0; i < k; i++) {
		isMove[y[i]][x[i]] = false;
	}
	for (auto i : friends) {
		isMove[y[i]][x[i]] = true;
	}

	vector<vector<ll>> dp(w + 1, vector<ll>(h + 1));
	dp[0][0] = 1LL;
	for (int i = 0; i <= w; i++) {
		for (int j = 0; j <= h; j++) {
			if (!isMove[i][j]) {
				continue;
			}

			dp[i][j] += 0 < i ? dp[i - 1][j] : 0;
			dp[i][j] += 0 < j ? dp[i][j - 1] : 0;
		}
	}

	return dp[w][h];

}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin >> h >> w >> k >> p;

	x.resize(k);
	y.resize(k);
	name.resize(k);

	for (int i = 0; i < k; i++) {
		cin >> x[i] >> y[i] >> name[i];
	}

	ll ans = 0, ansMask = 0;
	for (int mask = 0; mask < (1 << k); mask++) {
		ll score = f(mask);
		if (score <= ans) {
			continue;
		}

		ans = score;
		ansMask = mask;
	}

	const ll MOD = 1e9 + 7;
	ans %= MOD;

	cout << ans << endl;
	for (int i = 0; i < k; i++) {
		if (ansMask & (1 << i)) {
			cout << name[i] << endl;
		}
	}
	return 0;
}