#include <fstream>
using namespace std;
ifstream f("politie.in");
ofstream g("politie.out");
int n,m,d,p;
int main()
{
    f>>n>>m>>d>>p;
    int x,y,t,c,i,j;
    struct vec
    {
        int ca,pe;
    }v[50001];
    for(i=1;i<=m;i++)
    {
        f>>x>>y>>v[i].ca>>v[i].pe;
    }
    for(i=1;i<m;i++)
        for(j=i+1;j<=m;j++)
            if(v[i].pe<v[j].pe)
            {
                int aux=v[i].pe;
                v[i].pe=v[j].pe;
                v[j].pe=aux;
            }
    g<<v[1].pe<<endl;
    for(i=2;i<=p;i++)
        if(v[i].pe!=v[i-1].pe)
            g<<v[i].pe<<endl;
    return 0;
}