#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define int long long
//#define int double
typedef pair<int,int> pii;
typedef vector<pii> vii;
typedef vector<int> vi;
typedef vector<bool> vb;
#define FOR(i,a) for(int i=0;i<(a);i++)
#define FORE(i,a,b) for(int i=(a);i<(b);i++)
#define all(x) x.begin(),x.end()
#define fi first
#define se second
#define pb push_back
#define sp <<" "<<
#define cont(x) for(auto el:x) cout<<el<<' ';cout<<endl;
#define contp(x) for(auto el:x) cout<<el.fi<<'-'<<el.se<<' ';cout<<endl;
#define DEBUG(x) cout<<#x sp x<<endl;
#define carp(x,y) ((x%MOD)*(y%MOD))%MOD
#define topla(x,y) ((x%MOD)+(y%MOD))%MOD
#define mid (l+r)/2
const int MAXN=1e5+5;
const int MOD=1e9+7;
const int INF=1e18;
vii adj[MAXN];
bool vis[MAXN];
int tut[MAXN]; //pref xor
int p[MAXN], dep[MAXN];
map<int,set<int>> op;
map<pii,int> edg;
void dfs(int nd,int ata,int h){
vis[nd]=true;
dep[nd]=h;
p[nd]=ata;
for(auto [kom,cost]:adj[nd]){
if(!vis[kom]){
tut[kom]=tut[nd]^cost;
dfs(kom,nd,h+1);
}
else if(dep[kom]<dep[nd]){ //back edge
int deg=tut[nd]^tut[kom];
//back edgein vali (cost) == deg olmalı
if(deg!=cost) op[deg^cost].insert(edg[{nd,kom}]);
}
}
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int n,m;
cin>>n>>m;
FOR(i,m){
int a,b,c;
cin>>a>>b>>c;
adj[a].pb({b,c});
adj[b].pb({a,c});
edg[{a,b}]=i+1;
edg[{b,a}]=i+1;
}
dfs(1,0,0); //dfs tree oluştur
cout<<op.size()<<endl;
for(auto el:op){
cout<<el.fi<<' ';
cout<<el.se.size()<<' ';
for(auto el2:el.se) cout<<el2<<' ';
cout<<endl;
}
}
