#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstdio>
#include <queue>
#include <deque>
#include <bitset>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <random>
#include <ctime>
#include <utility>
#include <fstream>

#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("fast-math")
#pragma comment(linker, "/STACK:256000000")
#pragma warning(disable:4996)

using namespace std;

typedef long long ll;
typedef long double ld;

const char el = '\n';
const int inf = 1e9;
const ll llinf = 1e18, mod = 1000'000'007ll;
const ld pi = 3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825;

#define forn(i, n) for (int i = 0; i < (int)n; ++i)
#define firn(i, n) for (int i = 1; i < (int)n; ++i)
#define all(v) v.begin(), v.end()
#define x first
#define y second

template<typename T> bool uin(T &a, T b) { if (b < a) { a = b; return 1; } return 0; }
template<typename T> bool uax(T &a, T b) { if (b > a) { a = b; return 1; } return 0; }
template<class iterator> void output(iterator begin, iterator end, char p = ' ', ostream & out = cout) { while (begin != end) { out << (*begin) << p; begin++; } out << '\n'; }
template<class T> void output(T x, char p = ' ', ostream & out = cout) { output(all(x), p, out); }

mt19937 rnd(time(NULL));

vector<pair<int, int>> g[100000];

struct edge {
	int v, u;
	bool k;
};

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int n, m;
	cin >> n >> m;
	vector<int> r(n, 0);
	vector<edge> a(m);
	forn(i, m) {
		int v, u;
		cin >> v >> u;
		v--; u--;
		a[i] = { v, u, 1 };
		g[v].push_back({ u, i });
		g[u].push_back({ v, i });
	}
	vector<int> q, ans;
	q.push_back(0);
	while (!q.empty()) {
		int v = q.back();
		while (r[v] < (int)g[v].size() && !a[g[v][r[v]].y].k) r[v]++;
		if (r[v] < (int)g[v].size()) {
			q.push_back(g[v][r[v]].x);
			a[g[v][r[v]].y].k = 0;
			r[v]++;
		}
		else {
			ans.push_back(v + 1);
			q.pop_back();
		}
	}
	output(ans);
#ifdef _DEBUG
	system("pause");
#endif
	return 0;
}