#include<stdio.h>

 #include<string.h>

 #include<stdlib.h>

 #include<iostream>

 #include<queue>

 using namespace std;

 int vis[];

 int n,m,k;

 queue<int>q;

 struct node

 {

     int u,v;

     struct node *next;

 }*head[];

 void add(int u, int v)

 {

    struct node *p = (struct node*)malloc(sizeof(struct node));

    p->u = u;

    p->v = v;

    p->next = head[u];

    head[u] = p;

 };

 int cmp(const void *a,const void *b)

 {

     return *(int *)a-*(int *)b;

 }

 void bfs(int t)

 {

    int i,x,a[],j,b[],y;

    q.push(t);

    vis[t]=; j=;

    while(!q.empty())

    {

        x=q.front();

        a[++j]=x;

        q.pop();

        y=;

            for(struct node *p=head[x]; p!=NULL; p=p->next)

            {

                if(vis[p->v]==)

                {

                    b[y++]=p->v;

                    vis[p->v]=;

                }

            }

         if(y>=)

         qsort(b,y,sizeof(b[]),cmp);

         for(i=; i<=y-; i++)

         q.push(b[i]);

    }

    for(i=; i<=j-; i++)

    printf("%d ",a[i]);

    printf("%d\n",a[i]);

 };

 int main()

 {

     int t,i,u,v;

     scanf("%d",&n);

     while(n--)

     {

         memset(head,NULL,sizeof(head));

         memset(vis,,sizeof(vis));

         cin>>k>>m>>t;

         for(i=; i<m; i++)

         {

             cin>>u>>v;

             add(u,v);

             add(v,u);

         }

         bfs(t);

     }

 }