#include <stdio.h>
#include <vector>

using namespace std;
FILE *f=fopen("sortaret.in","r");
FILE *g=fopen("sortaret.out","w");

vector<int>l[50005],c;
int n,m,x,y,i,use[50005];


void df(vector<int>c)
{

for (vector<int>::iterator it=c.begin();it!=c.end();++it)
   {
     if (use[*it]==0){use[*it]=1;fprintf(g,"%d ",*it);df(l[*it]);}
   }
}

int main()
{

fscanf(f,"%d%d",&n,&m);
for(i=1;i<=m;i++)
{
 fscanf(f,"%d%d",&x,&y);
 l[x].push_back(y);
 l[y].push_back(x);
}

fprintf(g,"%d ",1);
for(i=1;i<=n;i++)
if (use[i]==0){if(i==1)use[i]=1;df(l[i]);}





fclose(g);
return 0;
}