#include <bits/stdc++.h>
#define fi first 
#define se second
#define mp make_pair
#define bit(n) (1LL << (n))
#define getbit(x, i) (((x) >> (i)) & 1)
#define pii pair <int, int>
#define ll long long
#define ALL(x) x.begin(), x.end()
#define pb push_back
using namespace std;
const int oo = 1e9;
const long long ooo = 1e18;

template<typename T1, typename T2> bool mini(T1 &a, T2 b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}

template<typename T1, typename T2> bool maxi(T1 &a, T2 b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
const int lim = 2e3 + 5;
struct disjoint_set {
    int h[lim], sz[lim];
    disjoint_set() {
        memset(h, -1, sizeof(h));
        fill(sz, sz + lim, 1);
    }
    int fh(int nd) {
        return h[nd] == -1 ? nd : h[nd] = fh(h[nd]);
    }
    bool same_par(int x, int y) {
        return fh(x) == fh(y);
    }
    bool merge(int x, int y) {
        x = fh(x), y = fh(y);
        if(x != y) {
            if(sz[x] < sz[y])
                swap(x, y);
            sz[x] += sz[y];
            h[y] = x;
        }
        return x != y;
    }
};
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    vector<pair<int, pair<int, int>>> init(m), adj;
    for(int i = 0; i < m; ++i) {
        cin >> init[i].se.fi >> init[i].se.se >> init[i].fi;
    }
    adj = init;
    ll minw = 0;
    sort(adj.begin(), adj.end());
    disjoint_set initdsu;
    for(auto x : adj) {
        if(initdsu.merge(x.se.fi, x.se.se)) {
            minw += x.fi;
        }
    }
    bool partmst[n - 1];
    memset(partmst, 0, sizeof(partmst));
    int cnt = 0;
    vector<pair<int, pair<int, int>>> cur;
    for(int i = 0; i < n - 1; ++i) {
        disjoint_set dsu;
        ll val = 0;
        for(auto x : cur)
            dsu.merge(x.se.fi, x.se.se), val += x.fi;
        dsu.merge(init[i].se.fi, init[i].se.se);
        val += init[i].fi;
        for(auto x : adj) {
            if(dsu.merge(x.se.fi, x.se.se))
                val += x.fi;
        }
        if(val == minw) {
            partmst[i] = true, cur.pb(init[i]);
        }
        else
            ++cnt;
    }
    cout << cnt << endl;
    cur.clear();
    for(int i = 0; i < n - 1; ++i)
        cur.pb(init[i]);
    for(int i = 0; i < n - 1; ++i) {
        // remove the i-th edge in init and change it with something else
        if(partmst[i])
            continue;
        pair<int, pair<int, int>> nxt;
        cur.erase(find(cur.begin(), cur.end(), init[i]));
        disjoint_set dsu;
        for(auto x : cur) {
            dsu.merge(x.se.fi, x.se.se);
        }
        for(auto x : adj) {
            if(dsu.merge(x.se.fi, x.se.se)) {
                nxt = x;
                break;
            }
        }
        // cerr << dsu.sz[dsu.fh(1)] << endl;
        // assert(dsu.sz[dsu.fh(1)] == n);
        // cout << dsu.sz[dsu.fh(1)] << endl;
        cur.pb(nxt);
        cout << i + 1 << " " << find(init.begin(), init.end(), nxt) - init.begin() + 1 << endl;
    }
    ll res = 0;
    for(auto x : cur) {
        res += x.fi;
    }
    // cerr << res << " " << minw << endl;
    // assert(res == minw);
    return 0;
}