#include <bits/stdc++.h>

using i64 = long long;

std::set<std::pair<int, int>> E;

struct EBCC {
    int n;
    std::vector<std::vector<int>> adj;
    std::vector<int> stk;
    std::vector<int> dfn, low, bel;
    int cur, cnt;
    
    EBCC() {}
    EBCC(int n) {
        init(n);
    }
    
    void init(int n) {
        this->n = n;
        adj.assign(n, {});
        dfn.assign(n, -1);
        low.resize(n);
        bel.assign(n, -1);
        stk.clear();
        cur = cnt = 0;
    }
    
    void addEdge(int u, int v) {
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    
    void dfs(int x, int p) {
        dfn[x] = low[x] = cur++;
        stk.push_back(x);
        
        for (auto y : adj[x]) {
            if (y == p) {
                continue;
            }
            if (dfn[y] == -1) {
                E.emplace(x, y);
                dfs(y, x);
                low[x] = std::min(low[x], low[y]);
            } else if (bel[y] == -1 && dfn[y] < dfn[x]) {
                E.emplace(x, y);
                low[x] = std::min(low[x], dfn[y]);
            }
        }
        
        if (dfn[x] == low[x]) {
            int y;
            do {
                y = stk.back();
                bel[y] = cnt;
                stk.pop_back();
            } while (y != x);
            cnt++;
        }
    }
    
    std::vector<int> work() {
        dfs(0, -1);
        return bel;
    }
    
    struct Graph {
        int n;
        std::vector<std::pair<int, int>> edges;
        std::vector<int> siz;
        std::vector<int> cnte;
    };
    Graph compress() {
        Graph g;
        g.n = cnt;
        g.siz.resize(cnt);
        g.cnte.resize(cnt);
        for (int i = 0; i < n; i++) {
            g.siz[bel[i]]++;
            for (auto j : adj[i]) {
                if (bel[i] < bel[j]) {
                    g.edges.emplace_back(bel[i], bel[j]);
                } else if (i < j) {
                    g.cnte[bel[i]]++;
                }
            }
        }
        return g;
    }
};

template<class T>
struct MaxFlow {
    struct _Edge {
        int to;
        T cap;
        _Edge(int to, T cap) : to(to), cap(cap) {}
    };
    
    int n;
    std::vector<_Edge> e;
    std::vector<std::vector<int>> g;
    std::vector<int> cur, h;
    
    MaxFlow() {}
    MaxFlow(int n) {
        init(n);
    }
    
    void init(int n) {
        this->n = n;
        e.clear();
        g.assign(n, {});
        cur.resize(n);
        h.resize(n);
    }
    
    bool bfs(int s, int t) {
        h.assign(n, -1);
        std::queue<int> que;
        h[s] = 0;
        que.push(s);
        while (!que.empty()) {
            const int u = que.front();
            que.pop();
            for (int i : g[u]) {
                auto [v, c] = e[i];
                if (c > 0 && h[v] == -1) {
                    h[v] = h[u] + 1;
                    if (v == t) {
                        return true;
                    }
                    que.push(v);
                }
            }
        }
        return false;
    }
    
    T dfs(int u, int t, T f) {
        if (u == t) {
            return f;
        }
        auto r = f;
        for (int &i = cur[u]; i < int(g[u].size()); ++i) {
            const int j = g[u][i];
            auto [v, c] = e[j];
            if (c > 0 && h[v] == h[u] + 1) {
                auto a = dfs(v, t, std::min(r, c));
                e[j].cap -= a;
                e[j ^ 1].cap += a;
                r -= a;
                if (r == 0) {
                    return f;
                }
            }
        }
        return f - r;
    }
    void addEdge(int u, int v, T c) {
        g[u].push_back(e.size());
        e.emplace_back(v, c);
        g[v].push_back(e.size());
        e.emplace_back(u, 0);
    }
    void addEdgeDir(int u, int v, T c) {
        g[u].push_back(e.size());
        e.emplace_back(v, c);
        g[v].push_back(e.size());
        e.emplace_back(u, c);
    }
    T flow(int s, int t) {
        T ans = 0;
        while (bfs(s, t)) {
            cur.assign(n, 0);
            ans += dfs(s, t, std::numeric_limits<T>::max());
        }
        return ans;
    }
    
    std::vector<bool> minCut() {
        std::vector<bool> c(n);
        for (int i = 0; i < n; i++) {
            c[i] = (h[i] != -1);
        }
        return c;
    }
    
    struct Edge {
        int from;
        int to;
        T cap;
        T flow;
    };
    std::vector<Edge> edges() {
        std::vector<Edge> a;
        for (int i = 0; i < e.size(); i += 2) {
            Edge x;
            x.from = e[i + 1].to;
            x.to = e[i].to;
            x.cap = e[i].cap + e[i + 1].cap;
            x.flow = e[i + 1].cap;
            a.push_back(x);
        }
        return a;
    }
};

constexpr int inf = 1E9 + 1;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int n, m;
    std::cin >> n >> m;

    EBCC ebcc(n);
    std::vector<std::map<int, int>> mp(n);
    for (int i = 0; i < m; i++) {
        int x, y, w;
        std::cin >> x >> y >> w;
        x--, y--;

        ebcc.addEdge(x, y);
        mp[x][y] = mp[y][x] = w;
    }

    ebcc.work();

    std::vector<int> mina(n, -1), minb(n, -1), maxa(n, -1), maxb(n, -1);
    std::vector<int> mine(n, inf), maxe(n, -inf);
    for (int i = 0; i < n; i++) {
        for (auto [j, w] : mp[i]) {
            if (ebcc.bel[i] == ebcc.bel[j]) {
                if (w < mine[ebcc.bel[i]]) {
                    mine[ebcc.bel[i]] = w;
                    mina[ebcc.bel[i]] = i;
                    minb[ebcc.bel[i]] = j;
                }
                if (w > maxe[ebcc.bel[i]]) {
                    maxe[ebcc.bel[i]] = w;
                    maxa[ebcc.bel[i]] = i;
                    maxb[ebcc.bel[i]] = j;
                }
            }
        }
    }

    int best = -1;
    for (int i = 0; i < n; i++) {
        if (best == -1 || maxe[i] - mine[i] >= maxe[best] - mine[best]) {
            best = i;
        }
    }

    MaxFlow<int> flow(n + 2);
    int s = n, t = s + 1;

    for (int i = 0; i < n; i++) {
        for (int j : ebcc.adj[i]) {
            if ((i == maxa[best] && j == maxb[best]) || (i == mina[best] && j == minb[best])) {
                continue;
            }
            if ((i == maxb[best] && j == maxa[best]) || (i == minb[best] && j == mina[best])) {
                continue;
            }
            if (ebcc.bel[i] == best && ebcc.bel[j] == best && i < j) {
                // std::cerr << i << " " << j << "\n";
                flow.addEdgeDir(i, j, 1);
            }
        }
    }
    flow.addEdge(s, mina[best], 1);
    flow.addEdge(s, minb[best], 1);
    flow.addEdge(maxa[best], t, 1);
    flow.addEdge(maxb[best], t, 1);

    int fl = flow.flow(s, t);
    assert(fl == 2);

    auto edges = flow.edges();

    std::vector<std::vector<int>> adj(n);
    for (auto [from, to, cap, flow] : edges) {
        if (flow == 2 && from != s && to != t) {
            adj[from].push_back(to);
            adj[to].push_back(from);
            if (n >= 50000) {
                std::cout << from << " " << to << "\n";
            }
        }
    }

    adj[mina[best]].push_back(minb[best]);
    adj[minb[best]].push_back(mina[best]);
    // std::cerr << mina[best] << " " << minb[best] << "\n";
    adj[maxa[best]].push_back(maxb[best]);
    adj[maxb[best]].push_back(maxa[best]);
    // std::cerr << maxa[best] << " " << maxb[best] << "\n";

    std::vector<std::map<int, int>> vis(n);

    std::vector<int> stk;
    auto dfs = [&](auto &&self, int x) -> void {
        for (int y : adj[x]) {
            if (vis[x][y]) {
                continue;
            }
            vis[x][y] = vis[y][x] = 1;
            self(self, y);
        }
        stk.push_back(x);
    };
    dfs(dfs, mina[best]);

    std::cout << maxe[best] - mine[best] << "\n";
    std::cout << stk.size() << "\n";
    for (int i = 0; i < stk.size(); i++) {
        std::cout << stk[i] + 1 << " \n"[i == stk.size() - 1];
    }

    return 0;
}