#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>

using namespace std;

ifstream fin("politie.in");
ofstream fout("politie.out");

int n, m, d, p, a, b, c, root[250005];
vector<pair<pair<int, int>, pair<int, int>>> edges;
priority_queue<int> pq;

int getRoot(int x)
{
    if ( root[x] != x )
        root[x] = getRoot(root[x]);
    return root[x];
}

void link(int x, int y)
{
    root[y] = x;
}

int main()
{
    fin >> n >> m >> d >> p;

    for ( int i = 1; i <= m; i++ )
    {
        fin >> a >> b >> c >> d;
        edges.push_back({ {c,d}, {a, b} });
    }

    for ( int i = 1; i <= n; i++ )
        root[i] = i;

    sort(edges.begin(), edges.end());

    for ( auto edge : edges )
    {
        int roota = getRoot(edge.second.first);
        int rootb = getRoot(edge.second.second);

        if ( roota != rootb )
        {
            link(roota, rootb);
            pq.push(edge.first.second);
        }
    }

    int last = -1;
    for ( int i = 1; i <= p; i++ )
    {
        if ( pq.top() == last )
        {
            i--;
            pq.pop();
            continue;
        }
        last = pq.top();
        fout << pq.top() << "\n", pq.pop();
    }


}