#include <bits/stdc++.h> #define nmax 103 #define mmax 10003 using namespace std; struct edge { int x, y; }; int n, m; int head[2 * nmax] = { 0 }, link[2 * mmax] = { 0 }, dd[nmax]; edge E[2 * mmax]; void BFS(int s) { deque<int> dq; dq.push_back(s); dd[s] = 1; vector<int> res; while (dq.size()) { int u = dq.front(); dq.pop_front(); res.push_back(u); int i = head[u]; while (i) { int v = E[i].y; if (!dd[v]) { dd[v] = 1; dq.push_back(v); } i = link[i]; } } for (int i = 0; i < res.size(); i++) cout << res[i] << "\n"; } int main() { ios::sync_with_stdio(0); cin.tie(0); cout.tie(0); cin >> n >> m; for (int i = 1; i <= 2 * m; i += 2) { int a, b; cin >> a >> b; E[i].x = a; E[i].y = b; E[i + 1].x = b; E[i + 1].y = a; } for (int i = 2 * m; i >= 1; i--) { link[i] = head[E[i].x]; head[E[i].x] = i; } for (int i = 1; i <= n; i++) if (!dd[i]) BFS(i); }