#include <bits/stdc++.h>

using namespace std;
typedef pair<int, int> pii;

struct Muchie
{
    int a, b, c;
    int other(int x)
    {
        return x == a ? b : a;
    }
};

bool cmp(const Muchie& a, const Muchie& b)
{
    return a.c > b.c;
}

int n, m;
vector<Muchie> q;
vector<Muchie> rez;
vector<pii> v[200001];
int viz[200001];
int dist;

int main()
{
    freopen("apm.in", "r", stdin);
    freopen("apm.out", "w", stdout);
    scanf("%d%d", &n, &m);
    int a, b, c;
    for(int i = 0; i < m; i++)
    {
        scanf("%d%d%d", &a, &b, &c);
        a--; b--;
        v[a].push_back(make_pair(b, c));
        v[b].push_back(make_pair(a, c));
    }
    viz[0] = 1;
    for(int i = 0; i < v[0].size(); i++)
    {
        q.push_back({0, v[0][i].first, v[0][i].second});
        push_heap(q.begin(), q.end(), cmp);
    }
    for(int i = 0; i < n - 1; i++)
    {
        Muchie top = q[0];
        pop_heap(q.begin(), q.end(), cmp);
        q.pop_back();
        if(viz[top.b])
        {
            i--;
            continue;
        }
        viz[top.b] = 1;
        dist += top.c;
        rez.push_back(top);
        for(int j = 0; j < v[top.b].size(); j++)
        {
            if(viz[v[top.b][j].first] == 0)
            {
                q.push_back({top.b, v[top.b][j].first, v[top.b][j].second});
                push_heap(q.begin(), q.end(), cmp);
            }
        }
    }
    printf("%d\n%d\n", dist, n - 1);
    for(int i = 0; i < n - 1; i++)
        printf("%d %d\n", rez[i].a + 1, rez[i].b + 1);

    return 0;
}