#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const ll INF = 1ll<<60;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int H, W, K, P;
int x[15], y[15];
string name[15];

bool done[33][33];
ll dp[33][33];

int main() {
	cin >> W >> H >> K >> P;
	REP(i, K) cin >> x[i] >> y[i] >> name[i];
	
	pll ans = pll(0, 0); // 数, 集合
	
	REP(s, 1<<K) {
		int cnt = 0;
		REP(i, K) if (s >> i & 1) cnt++;
		if (cnt > P) continue;
		
		memset(done, 0, sizeof(done));
		REP(i, K) if (!(s >> i & 1)) done[y[i]][x[i]] = true;
		
		memset(dp, 0, sizeof(dp));
		
		dp[0][0] = !done[0][0];
		
		REP(i, H + 1) REP(j, W + 1) {
			if (done[i][j]) continue;
			
			if (i > 0) dp[i][j] += dp[i - 1][j];
			if (j > 0) dp[i][j] += dp[i][j - 1];
		}
		
		chmax(ans, pll(dp[H][W], s));
	}
	
	printf("%lld\n", ans.first % MOD);
	REP(i, K) if (ans.second >> i & 1) printf("%s\n", name[i].c_str());
	
	return 0;
}