#include <bits/stdc++.h>
using namespace std;
#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repl(i,0,n)
#define mp(a,b) make_pair((a),(b))
#define pb(a) push_back((a))
#define all(x) (x).begin(),(x).end()
#define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x))
#define fi first
#define se second
#define dbg(x) cout<<#x" = "<<((x))<<endl
template<class T,class U> ostream& operator<<(ostream& o, const pair<T,U> &p){o<<"("<<p.fi<<","<<p.se<<")";return o;}
template<class T> ostream& operator<<(ostream& o, const vector<T> &v){o<<"[";for(T t:v){o<<t<<",";}o<<"]";return o;}

#define INF 2147483600123456
#define MOD 1000000007

long dp[35][35];
int fld[35][35];

int main(){
  int h,w,k,p;
  cin>>h>>w>>k>>p;
  fill(fld[0],fld[35],-1);
  vector<string> name(k);
  rep(i,k){
    int x,y;
    cin>>x>>y;
    fld[x][y] = i;
    cin>>name[i];
  }

  long mx = -1;
  long mmask = -1;
  rep(mask,1<<k) if(__builtin_popcount(mask)<=p){
    fill(dp[0], dp[35],0);
    dp[0][0]=1;
    rep(i,h+1)rep(j,w+1)if(fld[i][j]==-1 || (mask&(1<<fld[i][j])) ){
      dp[i+1][j] += dp[i][j];
      dp[i][j+1] += dp[i][j];
    }
    if(dp[h][w]>mx){
      mx = dp[h][w];
      mmask = mask;
    }
  }

  cout << mx%MOD << endl;
  rep(i,k) if(mmask&(1<<i)) cout <<name[i] << endl;


  return 0;
}