#include <bits/stdc++.h>

const int Nmax=100009;

using namespace std;

vector < vector <int> > ans;
vector <int> v[Nmax];
stack <int> stk;
int niv[Nmax],mi[Nmax],t[Nmax],n,m,x,y;

void dfs(int x)
{
    mi[x]=niv[x];
    stk.push(x);
    for(auto it:v[x])
    {
        if(it!=t[x])
        {
            if(niv[it])
            {
                mi[x]=min(mi[x],niv[it]);
            }
            else
            {
                t[it]=x;
                niv[it]=niv[x]+1;
                dfs(it);
                mi[x]=min(mi[x], mi[it]);
            }
        }
    }
    if(mi[x]>=niv[x]-1 && x!=1)
    {
        ans.push_back(*new vector <int>);
        while(stk.top()!=x)
        {
            ans.back().push_back(stk.top());
            stk.pop();
        }
        ans.back().push_back(stk.top());
        stk.pop();
        ans.back().push_back(t[x]);
    }
}

int main()
{
    ifstream fin ("biconex.in");
    ofstream fout ("biconex.out");
    fin>>n>>m;
    for(int i=1; i<=m; ++i)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    niv[1]=1;
    dfs(1);
    fout<<ans.size()<<"\n";
    for(int i=0; i<ans.size(); ++i)
    {
        for(auto it:ans[i])
        {
            fout<<it<<" ";
        }
        fout<<"\n";
    }
    return 0;
}