#include <iostream>
#include <algorithm>
#include <vector>
#include <map>

using namespace std;

struct Edge {
    int start;
    int end;
    int weight;
    double w;
};

int n, m;
int INF = 2147483647;
vector <double> d(1001, 0);
vector <Edge> ed;
int p[1001];
int b;
vector <int> ans;
map<pair<int, int>, int> mp;


void otvet() {
    ans.clear();
    int v = b;
    for (int i = 0; i < 2*n; i++) {
        v = p[v];
    }
    ans.push_back(v);
    int tmp = p[v];
    while(tmp != v) {
        ans.push_back(tmp);
        tmp = p[tmp];
    }
    reverse(ans.begin(), ans.end());
}


bool FB() {
    bool f = false;
    for (int k = 0; k < n - 1; k++)
        for (Edge e : ed)
            if (d[e.end] > d[e.start] + e.w) {
                d[e.end] = d[e.start] + e.w;
                p[e.end] = e.start;
            }
    for (Edge e: ed) {
        if (d[e.end] > d[e.start] + e.w) {
            b = e.end;
            p[b] = e.start;
            f = true;
            break;
            //return f;
        }
    }
    if (f)
        otvet();
    return f;
}


int main() {
    cin >> n >> m;
    int ma = 0;
    int mi = INF;
    for (int i = 0; i < m; i++) {
        Edge e;
        cin >> e.start >> e.end >> e.weight;
        e.w = e.weight;
        mp[make_pair(e.start, e.end)] = i + 1;
        mi = min(mi, e.weight);
        ma = max(ma, e.weight);
        ed.push_back(e);
    }

    double l = mi;
    double r = ma;
    double k = 1.0 / (n*n);
    while (r - l > k) {
        double mid = (l+r) / 2;
        for (int i = 0; i < ed.size(); i++) {
            ed[i].w = ed[i].weight - mid;
        }
        fill(d.begin(), d.end(), 0);
        bool g = FB();
        if(g)
            r = mid;
        else
            l = mid;
    }
    cout << l << "\n";
    cout << ans.size() << "\n";
    for (int i = 0; i < ans.size() - 1; i++) {
        cout << mp[make_pair(ans[i], ans[i+1])] << " ";
    }
    cout << mp[make_pair(ans[ans.size() - 1], ans[0])];

    return 0;
}