#include <iostream>#define MAX 9999using namespace std;int main(){    int i,j,n,m,cur,head,tail,e[101][101],q[100001],book[101]={0};    cin>>n>>m;    for(i=1;i<=n;i++)        for(j=1;j<=n;j++)    {        if(i==j)            e[i][j]=0;        else            e[i][j]=MAX;    }    int a,b;    for(i=1;i<=m;i++)    {        cin>>a>>b;        e[a][b]=1;        e[b][a]=1;    }    head=1;    tail=1;    q[tail]=1;    tail++;    book[1]++;    while(head<tail)    {        cur=q[head];        for(i=1;i<=n;i++)        {            if(e[cur][i]==1&&book[i]==0)        {            q[tail]=i;            tail++;            book[i]=1;        }        if(tail>n)            break;        }        head++;    }    for(int i=1;i<tail;i++)        cout<<q[i]<<endl;    return 0;}