#include <bits/stdc++.h>

#include <algorithm>
#include <cassert>
#include <limits>
#include <queue>
#include <vector>


#include <vector>

namespace atcoder {

namespace internal {

template <class T> struct simple_queue {
    std::vector<T> payload;
    int pos = 0;
    void reserve(int n) { payload.reserve(n); }
    int size() const { return int(payload.size()) - pos; }
    bool empty() const { return pos == int(payload.size()); }
    void push(const T& t) { payload.push_back(t); }
    T& front() { return payload[pos]; }
    void clear() {
        payload.clear();
        pos = 0;
    }
    void pop() { pos++; }
};

}  // namespace internal

}  // namespace atcoder


namespace atcoder {

template <class Cap> struct mf_graph {
  public:
    mf_graph() : _n(0) {}
    explicit mf_graph(int n) : _n(n), g(n) {}

    int add_edge(int from, int to, Cap cap) {
        assert(0 <= from && from < _n);
        assert(0 <= to && to < _n);
        assert(0 <= cap);
        int m = int(pos.size());
        pos.push_back({from, int(g[from].size())});
        int from_id = int(g[from].size());
        int to_id = int(g[to].size());
        if (from == to) to_id++;
        g[from].push_back(_edge{to, to_id, cap});
        g[to].push_back(_edge{from, from_id, 0});
        return m;
    }

    struct edge {
        int from, to;
        Cap cap, flow;
    };

    edge get_edge(int i) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        auto _e = g[pos[i].first][pos[i].second];
        auto _re = g[_e.to][_e.rev];
        return edge{pos[i].first, _e.to, _e.cap + _re.cap, _re.cap};
    }
    std::vector<edge> edges() {
        int m = int(pos.size());
        std::vector<edge> result;
        for (int i = 0; i < m; i++) {
            result.push_back(get_edge(i));
        }
        return result;
    }
    void change_edge(int i, Cap new_cap, Cap new_flow) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        assert(0 <= new_flow && new_flow <= new_cap);
        auto& _e = g[pos[i].first][pos[i].second];
        auto& _re = g[_e.to][_e.rev];
        _e.cap = new_cap - new_flow;
        _re.cap = new_flow;
    }

    Cap flow(int s, int t) {
        return flow(s, t, std::numeric_limits<Cap>::max());
    }
    Cap flow(int s, int t, Cap flow_limit) {
        assert(0 <= s && s < _n);
        assert(0 <= t && t < _n);
        assert(s != t);

        std::vector<int> level(_n), iter(_n);
        internal::simple_queue<int> que;

        auto bfs = [&]() {
            std::fill(level.begin(), level.end(), -1);
            level[s] = 0;
            que.clear();
            que.push(s);
            while (!que.empty()) {
                int v = que.front();
                que.pop();
                for (auto e : g[v]) {
                    if (e.cap == 0 || level[e.to] >= 0) continue;
                    level[e.to] = level[v] + 1;
                    if (e.to == t) return;
                    que.push(e.to);
                }
            }
        };
        auto dfs = [&](auto self, int v, Cap up) {
            if (v == s) return up;
            Cap res = 0;
            int level_v = level[v];
            for (int& i = iter[v]; i < int(g[v].size()); i++) {
                _edge& e = g[v][i];
                if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;
                Cap d =
                    self(self, e.to, std::min(up - res, g[e.to][e.rev].cap));
                if (d <= 0) continue;
                g[v][i].cap += d;
                g[e.to][e.rev].cap -= d;
                res += d;
                if (res == up) return res;
            }
            level[v] = _n;
            return res;
        };

        Cap flow = 0;
        while (flow < flow_limit) {
            bfs();
            if (level[t] == -1) break;
            std::fill(iter.begin(), iter.end(), 0);
            Cap f = dfs(dfs, t, flow_limit - flow);
            if (!f) break;
            flow += f;
        }
        return flow;
    }

    std::vector<bool> min_cut(int s) {
        std::vector<bool> visited(_n);
        internal::simple_queue<int> que;
        que.push(s);
        while (!que.empty()) {
            int p = que.front();
            que.pop();
            visited[p] = true;
            for (auto e : g[p]) {
                if (e.cap && !visited[e.to]) {
                    visited[e.to] = true;
                    que.push(e.to);
                }
            }
        }
        return visited;
    }

  private:
    int _n;
    struct _edge {
        int to, rev;
        Cap cap;
    };
    std::vector<std::pair<int, int>> pos;
    std::vector<std::vector<_edge>> g;
};

}  // namespace atcoder


namespace std {

template<class Fun>
class y_combinator_result {
	Fun fun_;
public:
	template<class T>
	explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}

	template<class ...Args>
	decltype(auto) operator()(Args &&...args) {
		return fun_(std::ref(*this), std::forward<Args>(args)...);
	}
};

template<class Fun>
decltype(auto) y_combinator(Fun &&fun) {
	return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}

} // namespace std

struct euler_tour_graph {
	int n, m;
	std::vector<int> degree, pos;
	std::vector<bool> visited;
	std::vector<std::vector<std::pair<int, int>>> adj;

	euler_tour_graph(int _n) : n(_n), m(0) {
		degree.resize(n);
		pos.resize(n);
		visited.resize(n);
		adj.resize(n);
	}

	void add_edge(int u, int v) {
		assert(0 <= u && u < n);
		assert(0 <= v && v < n);
		adj[u].emplace_back(v, m);
		adj[v].emplace_back(u, m);
		m++;
	}

	std::vector<int> euler_tour(int s) {
		fill(degree.begin(), degree.end(), 0);
		fill(pos.begin(), pos.end(), 0);
		visited.assign(m, false);

		std::vector<int> ret;
		std::stack<int> st;
		st.push(s);
		// degree[s]++;    // comment out to find tour instead of path
		while (!st.empty()) {
			int u = st.top();
			if (pos[u] == (int) adj[u].size()) {
				ret.push_back(u);
				st.pop();
				continue;
			}

			auto e = adj[u][pos[u]++];
			if (!visited[e.second]) {
				st.push(e.first);
				degree[u]--;
				degree[e.first]++;
				visited[e.second] = true;
			}
		}

		for (int i=0; i<n; i++)
			if (degree[i] < 0 || (int) ret.size() < m + 1)
				return {};
		return {ret.rbegin(), ret.rend()};
	}
};

int main() {
	using namespace std;

	int N, M;
	cin >> N >> M;
	vector<tuple<int, int, int>> E(M);
	vector<vector<pair<int, int>>> G(N);
	for (int i = 0; i < M; i++) {
		int u, v, w;
		cin >> u >> v >> w;
		u--, v--;
		G[u].emplace_back(v, w);
		G[v].emplace_back(u, w);
		E[i] = {u, v, w};
	}

	int tim = 0, scn = 0;
	vector<int> dfn(N, -1), low(N, -1), scc(N, -1);
	stack<int> stk;

	auto tarjan = y_combinator([&](auto self, int u, int p = -1) -> void {
		dfn[u] = low[u] = tim++;
		stk.push(u);
		for (auto [v, z] : G[u]) {
			if (dfn[v] == -1) {
				self(v, u);
				low[u] = min(low[u], low[v]);
			} else if (v != p) {
				low[u] = min(low[u], dfn[v]);
			}
		}
		if (low[u] == dfn[u]) {
			int v = -1;
			do {
				v = stk.top(); stk.pop();
				scc[v] = scn;
			} while (v != u);
			scn++;
		}
	});

	for (int i = 0; i < N; i++)
		if (dfn[i] == -1)
			tarjan(i);
	vector<int> rmn(scn, INT_MAX), rmx(scn, INT_MIN), num(scn, 0);
	for (auto [u, v, w] : E) {
		if (scc[u] != scc[v])
			continue;
		int s = scc[u];
		num[s]++;
		rmn[s] = min(rmn[s], w);
		rmx[s] = max(rmx[s], w);
	}
	int ans = INT_MIN, com = -1;
	for (int i = 0; i < scn; i++) {
		if (num[i] >= 2 && rmx[i] - rmn[i] > ans) {
			ans = rmx[i] - rmn[i];
			com = i;
		}
	}

	int su = -1, sv, tu, tv;
	for (auto [u, v, w] : E) {
		if (scc[u] != com || scc[v] != com)
			continue;
		if (w == rmx[com] && su == -1) 
			su = u, sv = v;
		else if (w == rmn[com])
			tu = u, tv = v;
	}
	atcoder::mf_graph<int> flo(N + 2);
	for (auto [u, v, w] : E) {
		if (scc[u] != com || scc[v] != com)
			continue;
		if ((u == su && v == sv) || (u == tu && v == tv))
			continue;
		flo.add_edge(u, v, 1);
		flo.add_edge(v, u, 1);
	}

	int ss = N, tt = N + 1;
	flo.add_edge(ss, su, 1);
	flo.add_edge(ss, sv, 1);
	flo.add_edge(tu, tt, 1);
	flo.add_edge(tv, tt, 1);
	assert(flo.flow(ss, tt) == 2);

	euler_tour_graph etg(N);
	map<pair<int, int>, int> sto;
	auto edg = flo.edges();
	for (auto [from, to, cap, flow] : edg) 
		if (flow == cap && from != ss && to != tt) 
			sto[{min(from, to), max(from, to)}]++;
	for (auto [p, n] : sto)
		if (n == 1)
			etg.add_edge(p.first, p.second);
	etg.add_edge(su, sv);
	etg.add_edge(tu, tv);
	auto ret = etg.euler_tour(su);

	assert(!ret.empty());
	ret.pop_back();
	cout << ans << '\n' << ret.size() << '\n';
	for (int u : ret)
		cout << u + 1 << ' ';
	cout << '\n';
}