#include <iostream>
#include <algorithm>
using namespace std;

using ll = long long;

int bitcount(int a){
	int r = 0;
	while(a){
		a -= a & -a;
		r++;
	}
	return r;
}

int main(){
	int h, w, k, p, ans = -1, maxi = -1;
	cin >> h >> w >> k >> p;
	int x[k], y[k];
	string n[k];
	for(int i = 0; i < k; i++) cin >> x[i] >> y[i] >> n[i];
	for(int puni = 0; puni < 1 << k; puni++){
		if(p < bitcount(puni)) continue;
		ll dp[h + 1][w + 1];
		fill(dp[0], dp[h + 1], -1);
		for(int i = 0; i < h + 1; i++) dp[i][0] = 1;
		for(int i = 0; i < w + 1; i++) dp[0][i] = 1;
		for(int i = 0; i < k; i++) if(!(puni >> i & 1)) dp[x[i]][y[i]] = 0;
		for(int i = 1; i < h + 1; i++) for(int j = 1; j < w + 1; j++) if(dp[i][j]){
			dp[i][j] = max(dp[i][j], dp[i - 1][j] + dp[i][j - 1]);
		}
		if(maxi < dp[h][w]){
			maxi = dp[h][w];
			ans = puni;
		}
	}
	if(maxi == -1){
		cout << 0 << endl;
		return 0;
	}
	cout << maxi % ll(1e9 + 7) << endl;
	for(int i = 0; i < k; i++) if(ans >> i & 1) cout << n[i] << endl;
}