#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;

const ll MAXN = 300001;

int n, m;

set<ll> edges;

vector<vi> C(MAXN, vi());

int color(ll i, ll j){
    if(edges.find(i*MAXN+j) == edges.end())return 1;
    return 0;
}

bool mark[MAXN] = {0};
set<int> S;
vi ans;

int grab(int i, int c){
    if(c == 0){
        trav(y, C[i]){
            if(!mark[y])return y;
        }
        return -1;
    }
    if(S.empty())return -1;
    auto it = S.end();
    it--;
    int j = 0;
    while(1){
        if(color(i, (*it)) == 1 && !mark[(*it)] && (*it) != i)return (*it);
        if(it == S.begin())return -1;
        it--;
        j++;
        if(j > max(20, 3*sz(C[i])))return -1;
    }
    return -1;
}

bool greedy(int i, int c, bool change){
    while(1){
        if(sz(S) == 1){
            ans.push_back(i);
            return 1;
        }
        int x = grab(i, c);
        if(x == -1){
            if(change){
                x = grab(i, c^1);
                change = 0;
                c ^= 1;
            }
        }
        if(x == -1)return 0;
        S.erase(i);
        mark[i] = 1;
        ans.push_back(i);
        i = x;
    }
  //  return greedy(x, c, change);
}

bool solve(int c){
    ans.clear();
    rep(c1,0,n){
        mark[c1] = 0;
        S.insert(c1);
        random_shuffle(all(C[c1]));
    }

    return greedy(0, c, 1);
}

int main() {
    cin >> n >> m;
    rep(c1,0,m){
        ll a,b;
        cin >> a >> b;
        a--;
        b--;
        edges.insert(a*MAXN+b);
        edges.insert(b*MAXN+a);
        C[a].push_back(b);
        C[b].push_back(a);
    }
    
    bool test;

    rep(c1,0,20){
        test = solve(c1%2);
        if(test)break;
    }

    if(!test){
        cout << "error\n";
        return 0;
    }

    rep(c1,0,n){
        cout << ans[c1]+1 << " ";
    }cout << "\n";

    return 0;
}