#include<bits/stdc++.h>
#define mp make_pair
#define fi first
#define se second
#define debug(x) cerr<<#x<<" = "<<(x)<<endl
#define eps 1e-8
#define pi acos(-1.0)
using namespace std;
void test(){cerr<<"\n";}
template<typename T,typename... Args>void test(T x,Args... args){cerr<<x<<" ";test(args...);}
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const int MAXN=(int)1e5+5;
const int MOD=(int)1e9+7;
struct edge{
int to,w,nxt;
}ed[MAXN*2];
int head[MAXN],cnt;
void addedge(int u,int v,int w){
ed[cnt]={v,w,head[u]};
head[u]=cnt++;
}
int val[MAXN];
bool vis[MAXN],ef[MAXN];
vector<pii>ve,vi;
vector<int>ans[35];
int a[35],p[35];
int main()
{
int n,m;
scanf("%d%d",&n,&m);
fill(head+1,head+1+n,-1);
for(int i=1;i<=m;i++){
int u,v,w;
scanf("%d%d%d",&u,&v,&w);
addedge(u,v,w);
addedge(v,u,w);
}
queue<int>q;
vis[1]=1;
q.push(1);
while(!q.empty()){
int u=q.front();q.pop();
for(int i=head[u];i!=-1;i=ed[i].nxt){
if(ef[i/2])continue;
ef[i/2]=1;
int v=ed[i].to,w=ed[i].w;
if(!vis[v]){
q.push(v);
vis[v]=1;
val[v]=val[u]^w;
}
else ve.push_back({w,i});
}
}
int num=0;
for(auto e:ve){
int u=ed[e.se].to,v=ed[e.se^1].to,w=ed[e.se].w;
int nd=val[u]^val[v]^w;
if(nd){
vi.push_back({nd,e.se/2+1});
for(int i=30;i>=0;i--){
if(!(nd>>i)&1)continue;
if(!a[i]){
a[i]=nd;
num++;
break;
}
nd^=a[i];
}
}
}
for(auto p:vi){
for(int i=30;i>=0;i--){
if(p.fi&(1<<i)){
ans[i].push_back(p.se);
p.fi^=a[i];
}
}
}
printf("%d\n",num);
for(int i=0;i<=30;i++){
if(a[i]){
printf("%d %d",a[i],(int)ans[i].size());
sort(ans[i].begin(),ans[i].end());
for(auto x:ans[i])printf(" %d",x);
printf("\n");
}
}
return 0;
}
