#include "bits/stdc++.h"
using namespace std;
#define all(x) begin(x),end(x)
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << '(' << p.first << ", " << p.second << ')'; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#define debug(a) cerr << "(" << #a << ": " << a << ")\n";
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const int mxN = 1e5+1, oo = 1e9;
vi adj[mxN];
vi base;
int pref[mxN];
bitset<mxN> vis,mark;
vector<array<int,3>> es;
vector<pi> bad;
void dfs(int at, int from) {
vis[at]=true;
mark[at]=true;
for(auto ei : adj[at]) {
auto& e = es[ei];
int to = e[0]^e[1]^at, w= e[2];
if(to==from) continue;
if(!vis[to]) {
pref[to]=pref[at]^w;
dfs(to,at);
} else if(mark[to]) {
// back edge
int cyc = pref[at]^pref[to]^w;
bad.push_back({ei,cyc});
for(auto i : base) cyc = min(cyc,i^cyc);
if(cyc!=0) base.push_back(cyc);
}
}
mark[at]=false;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n,m; cin >> n >> m;
es.resize(m);
for(int i=0;i<m;++i) {
auto& [a,b,w] = es[i];
cin >> a >> b >> w;
adj[a].push_back(i);
adj[b].push_back(i);
}
dfs(1,0);
vvi res(base.size());
sort(all(bad));
for(auto [i,cyc] : bad) {
for(int j=0;j<(int)base.size();++j) {
if((cyc^base[j]) < cyc) {
cyc ^=base[j];
res[j].push_back(i+1);
}
}
}
cout << base.size() << '\n';
auto it = base.begin();
for(auto& i : res) {
cout << *(it++) << ' ';
cout << i.size() << ' ';
cout << i << '\n';
}
}
