#include <bits/stdc++.h>

using namespace std;

ifstream fin("modern.in");
ofstream fout("modern.out");

int parent[110], rnk[110];


struct da {
    int f, t, cost;
};

bool comp(da a, da b)
{
    return a.cost < b.cost;
}

vector < da > v;
vector < pair < int, int > > muuu;

int n, m, cT;

int ufind(int nod)
{
    while (parent[nod] != nod)
    {
        parent[nod] = parent[parent[nod]];
        nod = parent[nod];
    }

    return nod;
}

void unite(int a, int b)
{
    if (rnk[a] > rnk[b])
        parent[b] = a;
    else
        parent[a] = b;

    if (rnk[a] == rnk[b])
        rnk[b]++;
}

void Kruskal()
{
    for (da el : v)
    {
        int rootF = ufind(el.f), rootT = ufind(el.t);

        if (rootF != rootT)
        {
            muuu.push_back({el.f, el.t});

            cT += el.cost;
            unite(rootT, rootF);
        }
    }
}

int main()
{
    fin >> n >> m;

    muuu.reserve(m);

    for (int i = 1; i <= m; i++)
    {
        int a, b, c;

        fin >> a >> b >> c;

        v.push_back({a, b, c});
    }

    sort(v.begin(), v.end(), comp);

    for (int i = 1; i <= n; i++)
        parent[i] = i, rnk[i] = 1;


    Kruskal();



    for (auto el : muuu)
    {
        fout << el.first << ' ' << el.second << '\n';
    }

    fout << cT * 100 << '\n';


    fin.close();
    fout.close();
    return 0;
}