#include <bits/stdc++.h>

using namespace std;
ifstream fin ("fof.in");
ofstream fout ("fof.out");
int a, n, m;
vector <int> v[1001];
vector <int> r;
queue <int> Q;
queue <int> R;
int viz[1001];
int drum[1000001];
int x, y;
void BFS (int a)
{
    Q.push(a);
    while(!Q.empty())
    {
        int nod= Q.front();
        Q.pop();
        for(auto it : v[nod])
        {
            if(!viz[it]&&it!=nod)
            {
                drum[it]=drum[nod]+1;
                viz[it]=1;
                if(drum[it]!=2)
                    Q.push(it);
                else r.push_back(it);
            }
        }
    }
}
int main()
{
    fin>>n>>m;
    for (int i=1; i<=m; i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        viz[i]=1;
        BFS(i);
        if(!r.empty())
        {
            sort(r.begin(),r.end()-1);
        }


        for(int j=0; j<r.size(); j++)
        {
            fout<<r[j]<<" ";

        }

        fout<<endl;
        r.clear();

        for(int j=1; j<=n; j++)
        {
            viz[j]=0;
            drum[j]=0;
        }

    }



    return 0;
}