#include <bits/stdc++.h>
using namespace std;
void fastIO(){ios_base::sync_with_stdio(false),cin.tie(0);}
#define int long long
#define f first
#define s second
const int MAXV = 100'020;
int V, E;
struct Edge {
int to, cost, idx;
};
vector<Edge> adj[MAXV];
int depth[MAXV];
int rootPath[MAXV];
map<int, vector<int>> toChange;
void dfs (int node, int par) {
for (Edge nxt : adj[node]) {
int child = nxt.to, cost = nxt.cost, idx = nxt.idx;
if (child == par) {
continue;
}
else if (rootPath[child] == -1) {
rootPath[child] = rootPath[node] ^ cost;
dfs(child, node);
}
else {
int underCost = rootPath[node] ^ rootPath[child];
int xorVal = cost ^ underCost;
if (xorVal != 0 && toChange.find(xorVal) == toChange.end()) {
toChange[xorVal] = {idx};
}
else if (xorVal != 0) {
toChange[xorVal].push_back(idx);
}
}
}
}
signed main() {
fastIO();
cin >> V >> E;
for (int i = 0; i < E; i++) {
int u, v, c;
cin >> u >> v >> c;
u--, v--;
adj[u].push_back({v, c, i});
adj[v].push_back({u, c, i});
}
fill(rootPath, rootPath+V, -1);
rootPath[0] = 0;
dfs(0, -1);
cout << (int)toChange.size() << "\n";
for (auto lIt = toChange.begin(); lIt != toChange.end(); lIt++) {
pair<int,vector<int>> on = *lIt;
sort(on.s.begin(), on.s.end());
on.s.erase(unique(on.s.begin(), on.s.end()), on.s.end());
cout << on.f << " " << (int)on.s.size() << " ";
for (int val : on.s) {
cout << val+1 << " ";
}
cout << "\n";
}
}
