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


const int MOD = 1000000007;


long long solve(const vector<vector<bool> >& block){
	int h = block.size();
	int w = block[0].size();

	vector<vector<long long> > dp(h+1, vector<long long>(w+1, 0));
	dp[0][0] = 1;
	for(int y=0; y<h; ++y){
		for(int x=0; x<w; ++x){
			if(!block[y][x]){
				dp[y+1][x] += dp[y][x];
				dp[y][x+1] += dp[y][x];
			}
		}
	}
	
	return dp[h-1][w-1];
}


int main(){
	int h, w, n, p;
	cin >> h >> w >> n >> p;
	vector<int> y(n), x(n);
	vector<string> name(n);
	
	for(int i=0; i<n; ++i)
		cin >> y[i] >> x[i] >> name[i];

	long long MX = 0;
	bitset<32> ans;
	for(int i=0; i<(1<<n); ++i){
		bitset<32> bs(i);
		if(bs.count() != p)
			continue;

		vector<vector<bool> > block(h+1, vector<bool>(w+1, false));
		for(int j=0; j<n; ++j){
			if(!bs[j])
				block[y[j]][x[j]] = true;
		}
		
		long long res = solve(block);
			if(MX < res){
				MX = res;
				ans = bs;
			}
	}

	MX %= MOD;
	cout << MX << endl;
	for(int i=0; i<n; ++i){
		if(ans[i])
		cout << name[i] << endl;
	}

	return 0;
}