#include <utility>   
#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
using namespace std;
ifstream f("biconex.in");
ofstream g("biconex.out");
stack < pair<int,int> >muchii;
vector<int>*a;
int **comp;
int *viz,*hgh,cnt=0;
void dfs(int st)
{
	viz[st]=1;
	//hgh[st]=h;
	for(int j=0;j<a[st].size();j++)
		if(viz[a[st][j]]!=1)
		{
			int k=a[st][j];
			muchii.push(make_pair(st,k));
			hgh[k]=hgh[st]+1;
			for(int i=0;i<a[k].size();i++)
			{
				if(hgh[k]>hgh[a[k][i]]+1)hgh[k]=hgh[a[k][i]]+1;
			}
			dfs(k);
			if(hgh[st]<hgh[muchii.top().second])
			{	cnt++;
				comp[cnt][0]=0;
				while(!(muchii.top().first==st&&muchii.top().second==k))
				{
					comp[cnt][++comp[cnt][0]]=muchii.top().second;
					//cout<<muchii.top().second<<" ";
					muchii.pop();
				}
				//cout<<muchii.top().second<<" "<<muchii.top().first;
				comp[cnt][++comp[cnt][0]]=muchii.top().second;
				comp[cnt][++comp[cnt][0]]=muchii.top().first;
				muchii.pop();
				//cout<<endl;
			}
			
		}
	
}
int main()
{
	int n,m;
	
	f>>n>>m;
	viz=new int[n+1];
	hgh=new int[n+1];
	comp=new int*[n+1];
	for(int i=1;i<=n;i++)
	{
		comp[i]=new int[n+1];
	}
	a=new vector<int>[n+1];
	for(int i=1;i<=m;i++)
	{
		int x,y;
		f>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
	f.close();
	/*
	for(int i=1;i<=n;i++)
	{
		for(int j=0;j<a[i].size();j++)
			cout<<a[i][j]<<" ";
		cout<<endl;
	}*/
	hgh[1]=0;
	dfs(1);
	

	//for(int i=1;i<=n;i++)cout<<hgh[i]<<" ";
	g<<cnt<<endl;
	
	for(int i=1;i<=cnt;i++)
	{
		for(int j=1;j<=comp[i][0];j++)
			g<<comp[i][j]<<" ";
		g<<endl;
	}
	return 0;
}