#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <stack>
#include <algorithm>
using namespace std;
ifstream in("apm.in");
ofstream out("apm.out");
class graph{
int n, ct, sum;
vector < vector < int > > G, ReverseG, sol;
queue < int > Bfs;
stack < int > Ctc, Topo, Biconex;
vector < bool > vis, vis2;
vector < int > level, low, mult, sz;
vector < pair < int, int > > sol_apm;
struct muchie
{
int left, right, cost;
};
vector < muchie > apm;
struct comp
{
inline bool operator() (const muchie& a, const muchie& b)
{
return a.cost < b.cost;
}
};
void bfs(int source)
{
vector < int > nodes;
nodes.resize(n + 1, -1);
Bfs.push(source); nodes[source] = 0;
while(!Bfs.empty())
{
int node = Bfs.front();
Bfs.pop();
for(int i = 0; i < G[node].size(); ++i)
{
int nnode = G[node][i];
if(nodes[nnode] == -1)
{
nodes[nnode] = nodes[node] + 1;
Bfs.push(nnode);
}
}
}
for(int i = 1; i <= n; ++i)
out << nodes[i] << " ";
}
void dfs(int node)
{
vis[node] = 1;
for(int i = 0; i < G[node].size(); ++i)
{
int nnode = G[node][i];
if(vis[nnode] == 0)
dfs(nnode);
}
}
void dfs_ctc_1(int node)
{
vis[node] = 1;
for(int i = 0; i < G[node].size(); ++i)
{
int nnode = G[node][i];
if(vis[nnode] == 0)
dfs_ctc_1(nnode);
}
Ctc.push(node);
}
void dfs_ctc_2(int node)
{
vis2[node] = 1;
sol[ct - 1].push_back(node);
for(int i = 0; i < ReverseG[node].size(); ++i)
{
int nnode = ReverseG[node][i];
if(vis2[nnode] == 0)
dfs_ctc_2(nnode);
}
}
void dfs_topo(int node)
{
vis[node] = 1;
for(int i = 0; i < G[node].size(); ++i)
{
int nnode = G[node][i];
if(vis[nnode] == 0)
dfs_topo(nnode);
}
Topo.push(node);
}
void dfs_biconex(int node, int dad)
{
vis[node] = 1;
level[node] = level[dad] + 1;
low[node] = level[node];
for(int i = 0; i < G[node].size(); ++i)
{
int nnode = G[node][i];
if(nnode != dad)
{
if(vis[nnode] == 1)
{
if(level[nnode] < low[node])
low[node] = level[nnode];
}
else
{
Biconex.push(nnode);
dfs_biconex(nnode, node);
if(low[nnode] < low[node])
low[node] = low[nnode];
if(level[node] <= low[nnode])
{
++ct;
Biconex.push(node);
while(!Biconex.empty() && Biconex.top() != nnode)
{
sol[ct - 1].push_back(Biconex.top());
Biconex.pop();
}
if(!Biconex.empty())
{
sol[ct - 1].push_back(Biconex.top());
Biconex.pop();
}
}
}
}
}
}
void dfs_muchii(int node, int dad)
{
vis[node] = 1;
if(dad == -1) level[node] = 1;
else level[node] = level[dad] + 1;
low[node] = level[node];
for(int i = 0; i < G[node].size(); ++i)
{
int nnode = G[node][i];
if(nnode != dad)
{
if(vis[nnode] == 1)
{
if(level[nnode] < low[node])
low[node] = level[nnode];
}
else
{
dfs_muchii(nnode, node);
if(low[nnode] < low[node])
low[node] = low[nnode];
if(level[node] < low[nnode])
{
++ct;
sol.push_back({node, nnode});
}
}
}
}
}
int Find(int val)
{
int root = val, aux;
while(mult[root] != root)
root = mult[root];
while(mult[val] != root)
{
aux = mult[val];
mult[val] = root;
val = aux;
}
return root;
}
void Union(int a, int b)
{
int rootA, rootB;
rootA = Find(a);
rootB = Find(b);
if(sz[rootA] < sz[rootB])
{
sz[rootB] += sz[rootA];
mult[rootA] = rootB;
}
else
{
sz[rootA] += sz[rootB];
mult[rootB] = rootA;
}
}
public:
void solve_bfs()
{
int m, s, x, y;
in >> n >> m >> s;
G.resize(n + 1);
for(int i = 0; i < m; ++i)
{
in >> x >> y;
G[x].push_back(y);
}
bfs(s);
}
void solve_dfs()
{
int m, x, y, ct = 0;
in >> n >> m;
G.resize(n + 1);
vis.resize(n + 1, false);
for(int i = 0; i < m; ++i)
{
in >> x >> y;
G[x].push_back(y);
G[y].push_back(x);
}
for(int i = 1; i <= n; ++i)
if(vis[i] == 0)
{
++ct;
dfs(i);
}
out << ct;
}
void solve_ctc()
{
int m, x, y;
in >> n >> m;
G.resize(n + 1);
ReverseG.resize(n + 1);
sol.resize(n + 1);
vis.resize(n + 1, false);
vis2.resize(n + 1, false);
for(int i = 1; i <= m; ++i)
{
in >> x >> y;
G[x].push_back(y);
ReverseG[y].push_back(x);
}
for(int i = 1; i <= n; ++i)
if(vis[i] == 0)
dfs_ctc_1(i);
ct = 0;
while(!Ctc.empty())
{
int node = Ctc.top();
Ctc.pop();
if(vis2[node] == 0)
{
++ct;
dfs_ctc_2(node);
}
}
out << ct << "\n";
for(int i = 0; i < ct; ++i)
{
for(int j = 0; j < sol[i].size(); ++j)
out << sol[i][j] << " ";
out << "\n";
}
}
void solve_topo()
{
int m, x, y;
in >> n >> m;
G.resize(n + 1);
vis.resize(n + 1, false);
for(int i = 1; i <= m; ++i)
{
in >> x >> y;
G[x].push_back(y);
}
for(int i = 1; i <= n; ++i)
if(vis[i] == 0)
dfs_topo(i);
while(!Topo.empty())
{
int node = Topo.top();
Topo.pop();
out << node << " ";
}
}
void solve_biconex()
{
int m, x, y;
in >> n >> m;
G.resize(n + 1);
sol.resize(n + 1);
level.resize(n + 1, 0);
low.resize(n + 1, 0);
vis.resize(n + 1, false);
for(int i = 1; i <= m; ++i)
{
in >> x >> y;
G[x].push_back(y);
G[y].push_back(x);
}
ct = 0;
dfs_biconex(1, 0);
out << ct << "\n";
for(int i = 0; i < ct; ++i)
{
for(int j = 0; j < sol[i].size(); ++j)
out << sol[i][j] << " ";
out << "\n";
}
}
vector<vector<int>> criticalConnections(int nr, vector<vector<int>>& connections)
{
n = nr;
ct = 0;
G.resize(n + 1);
level.resize(n + 1, 0);
low.resize(n + 1, 0);
vis.resize(n + 1, false);
for(int i = 0; i < connections.size(); ++i)
{
int x = connections[i][0];
int y = connections[i][1];
G[x].push_back(y);
G[y].push_back(x);
}
dfs_muchii(0, -1);
return sol;
}
void solve_disjoint()
{
int m, task, x, y;
in >> n >> m;
mult.resize(n + 1, 0);
sz.resize(n + 1, 1);
for(int i = 1; i <= n; ++i)
mult[i] = i;
for(int i = 0; i < m; ++i)
{
in >> task >> x >> y;
if(task == 1)
{
Union(x, y);
}
else
{
int root1 = Find(x);
int root2 = Find(y);
if(root1 == root2) out << "DA" << "\n";
else out << "NU" << "\n";
}
}
}
void solve_apm()
{
int m;
in >> n >> m;
mult.resize(n + 1, 0);
sz.resize(n + 1, 1);
apm.resize(m + 1);
for(int i = 1; i <= n; ++i)
mult[i] = i;
for(int i = 0; i < m; ++i)
in >> apm[i].left >> apm[i].right >> apm[i].cost;
sort(apm.begin(), apm.end(), comp());
sum = 0;
for(int i = 0; i < m; ++i)
{
int a = apm[i].left;
int b = apm[i].right;
int root_a = Find(a);
int root_b = Find(b);
if(root_a != root_b)
{
Union(a, b);
sol_apm.push_back(make_pair(a, b));
sum += apm[i].cost;
}
}
out << sum << "\n" << sol_apm.size() << "\n";
for(int i = 0; i < sol_apm.size(); ++i)
out << sol_apm[i].first << " " << sol_apm[i].second << "\n";
}
};
int main()
{
graph G;
G.solve_apm();
return 0;
}