1 #include<iostream>
2 #include<cstdio>
3 using namespace std;
4 int que[10000];
5 int vis[10000];
6 int map[1000][1000];
7 int n,m;
8 void bfs(int u)
9 {
10 cout<<char(u+65)<<" ";
11 int head=0;
12 int tail=1;
13 que[tail]=u;
14 vis[u]=1;
15 while(head<tail)
16 {
17 head++;
18 int k=que[head];
19 for(int i=1;i<=n;i++)
20 {
21 if(map[k][i]==1&&vis[i]==0)
22 {
23 tail++;
24 que[tail]=i;
25 cout<<char(i+65)<<" ";
26 vis[i]=1;
27 }
28 }
29 }
30 }
31 int main()
32 {
33 cin>>n>>m;
34 char x,y;
35 for(int i=1;i<=m;i++)
36 {
37 cin>>x>>y;
38 map[x-64-1][y-64-1]=1;
39 map[y-64-1][x-64-1]=1;
40 }
41 bfs(0);
42 return 0;
43 }
