#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define pi M_PI
#define R cin>>
#define Z class
#define ll long long
#define ln cout<<'\n'
#define in(a) insert(a)
#define pb(a) push_back(a)
#define pd(a) printf("%.10f\n",a)
#define mem(a) memset(a,0,sizeof(a))
#define all(c) (c).begin(),(c).end()
#define iter(c) __typeof((c).begin())
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
template<Z A>void pr(A a){cout<<a;ln;}
template<Z A,Z B>void pr(A a,B b){cout<<a<<' ';pr(b);}
template<Z A,Z B,Z C>void pr(A a,B b,C c){cout<<a<<' ';pr(b,c);}
template<Z A,Z B,Z C,Z D>void pr(A a,B b,C c,D d){cout<<a<<' ';pr(b,c,d);}
template<Z A>void PR(A a,ll n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
ll check(ll n,ll m,ll x,ll y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1000000007,MAXL=1LL<<61,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<int,int> P;

void Main() {
  int h,w,n,p;
  cin >> h >> w >> n >> p;
  h++,w++;
  string s[n];
  int a[h][w];
  memset(a,-1,sizeof(a));
  rep(i,n) {
    int x,y;
    cin >> x >> y >> s[i];
    a[x][y]=i;
  }
  ll ans=0;
  vector<string> v;
  rep(t,1<<n) {
    if(__builtin_popcount(t)>p) continue;
    ll dp[h][w];
    memset(dp,0,sizeof(dp));
    dp[0][0]=1;
    rep(i,h)rep(j,w) {
      REP(k,1,3) {
        int x=i+dx[k],y=j+dy[k];
        if(!check(h,w,x,y)) continue;
        if(a[x][y]!=-1&&!(t&(1<<a[x][y]))) continue;
        dp[x][y]+=dp[i][j];
      }
    }
    if(dp[h-1][w-1]>ans) {
      ans=dp[h-1][w-1];
      v.clear();
      rep(i,n) if(t&(1<<i)) v.pb(s[i]);
    }
  }
  pr(ans%MAX);
  rep(i,v.size()) pr(v[i]);
}

int main(){ios::sync_with_stdio(0);cin.tie(0);Main();return 0;}