#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
using namespace std;

#define MOD 1000000007

int h;
int w;
int k;
int p;


struct st{
	int x;
	int y;
	string name;
};

vector<st> v;
char buf[20];

bool ng[40][40];

long double dp[40][40];

vector<string> ans;

int main(){
	cin >> h >> w >> k >> p;
	for (int i = 0; i < k; i++){
		int a, b;
		scanf("%d%d", &a, &b);
		scanf("%s", buf);
		v.push_back({ a, b, buf });
	}
	int id = 0;
	long double val = 0;
	for (int i = 0; i < (1 << k); i++){
		int give = 0;
		memset(ng, false, sizeof(ng));
		for (int j = 0; j < k; j++){
			if ((i >> j) & 1){
				give++;
			}
			else{
				ng[v[j].x][v[j].y] = true;
			}
		}
		if (give > p)continue;
		for (int i = 0; i <= h; i++){
			for (int j = 0; j <= w; j++){
				dp[i][j] = 0;
			}
		}
		dp[0][0] = 1;
		for (int i = 0; i <= h; i++){
			for (int j = 0; j <= w; j++){
				if (!ng[i + 1][j]){
					dp[i + 1][j] += dp[i][j];
				}
				if (!ng[i][j + 1]){
					dp[i][j+1] += dp[i][j];
				}
			}
		}
		if (val < dp[h][w]){
			val = dp[h][w];
			id = i;
		}
	}
	int i = id;
	memset(ng, false, sizeof(ng));
	for (int i = 0; i <= h; i++){
		for (int j = 0; j <= w; j++){
			dp[i][j] = 0;
		}
	}
	for (int j = 0; j < k; j++){
		if ((i >> j) & 1){
			ans.push_back(v[j].name);
		}
		else{
			ng[v[j].x][v[j].y] = true;
		}
	}
	dp[0][0] = 1;
	for (int i = 0; i <= h; i++){
		for (int j = 0; j <= w; j++){
			dp[i][j] = (long long int)(dp[i][j]) % MOD;
			if (!ng[i + 1][j]){
				dp[i + 1][j] += dp[i][j];
			}
			if (!ng[i][j + 1]){
				dp[i][j + 1] += dp[i][j];
			}
		}
	}
	printf("%lld\n", (long long int)dp[h][w]);
	for (int i = 0; i < ans.size(); i++){
		printf("%s", ans[i].c_str());
		puts("");
	}
	return 0;
}