#include<bits/stdc++.h>
using namespace std;
vector<int>graph[1001];
int visit[1001];
int n, e;
void DFS(int start)
{
//Using Stack
//Initial Steps
visit[start] = 1;
stack<int>STK;
STK.push(start);
cout<<start<<" ";
//Repeating step
int x = STK.top();
while(!STK.empty())
{
for(int j = 0; j < graph[x].size(); j++)
{
x = STK.top();
int nd = graph[x][j];
if(visit[nd] == 0)
{
visit[nd] = 1;
STK.push(nd);
cout<<nd<<" ";
j = 0;
}
}
STK.pop();
}
}
void DFS_RC(int start)
{
visit[start] = 1;
cout<<start<<" ";
for(int j = 0; j < graph[start].size();j++)
{
int node = graph[start][j];
if(visit[node] == 0)
{
visit[node] = 1;
DFS_RC(node);
}
}
}
int main()
{
cin>>n>>e;
int u, v;
for(int i = 1; i <= e; i++)
{
cin>>u>>v;
graph[u].push_back(v);
graph[v].push_back(u);
}
DFS(1);
//DFS_RC(1);
}
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