#include <iostream>

#include <vector>

#include <tuple>

#include <algorithm>

using namespace std;

vector< tuple<int, int, int> > edge;

vector<int> parents;

vector<int> ranks;

bool cmp(tuple<int, int, int> s1, tuple<int, int, int> s2)

{

    return get<2>(s1) < get<2>(s2);

}

bool union_find(int u, int v)

{

    // find root of u and v

    while (u != parents[u]) u = parents[u];

    while (v != parents[v]) v = parents[v];

    // circle

    if (u == v) return false;

    if (ranks[u] > ranks[v]) parents[v] = u;

    else if (ranks[v] > ranks[u]) parents[u] = v;

    else parents[v] = u, ++ranks[u];

    return true;

}

void kruskcal()

{

    sort(edge.begin(), edge.end(), cmp);

    bool forest = true;

    for (auto& [u, v, w] : edge) if (!union_find(u, v))

    {

        if (!forest) cout << " ";

        cout << w;

        forest = false;

    }

    if (forest) cout << "forest";

    cout << "\n";

}

int main()

{

    // fast io

    ios::sync_with_stdio(false);

    cin.tie(nullptr);

    cout.tie(nullptr);

    int n, m;

    while (cin >> n >> m, n && m)

    {

        // init

        edge.clear();

        parents.clear();

        ranks.assign(n, 0);

        for (int i = 0; i < n; ++i) parents.emplace_back(i);

        // store side and weight

        while (m--)

        {

            int u, v, w;

            cin >> u >> v >> w;

            edge.push_back({ u, v, w });

        }

        // kruskcal algorithm

        kruskcal();

    }

    return 0;

}