#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;;
#define ll long long
#define ar array
template<typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
#define all(v) v.begin(), v.end()
#define ld long double
const int N = 4e5 + 20;
const int M = 2;
const int LOG = 20;
const ll INF = 1e17;
int MOD = 998244353;
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// //#pragma GCC optimize("unroll-loops")
template<typename T>
inline void chmin(T &x,T y){x = min(x, y);}
template<typename T>
inline void chmax(T &x,T y){x = max(x, y);}
inline void mm(int &x){x = (x % MOD + MOD) % MOD;};
bool vis[N];
set<int> g[N];
vector<int> P;
vector<int> Q;
void dfs(int x,int p,int s){
P.push_back(x);
vis[x] = 1;
//cout<<1 + x<<' ';
for(auto u: g[x]){
if(u == p)continue;
if(u == s){
Q = P;
return;
}
if(!vis[u])dfs(u, x, s);
}
P.pop_back();
}
void orz(){
int n, m;
cin>>n>>m;
for(int i = 0;i < m;i++){
int a, b;
cin>>a>>b;
--a, --b;
g[a].insert(b);
g[b].insert(a);
}
for(int i = 0;i < n;i++){
while(g[i].size() > 0){
P.clear();
Q.clear();
dfs(i, i, i);
for(auto u: Q)cout<<u + 1<<" ";
cout<<'\n';
int y = Q.back();
for(auto x: Q){
g[y].erase(x);
g[x].erase(y);
y = x;
}
for(int i = 0;i < n;i++)vis[i] = 0;
}
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
//cin>>t;
while (t--)orz();
}
//I am stupid :D
