5 5
1 2
1 3
1 4
1 5
2 3

1 4
1 2 3 4 5

from collections import deque
n,m=map(int,input().split())
graph=[[] for _ in range(n+1)]
for _ in range(m):
    u,v=map(int,input().split())
    graph[u].append(v); graph[v].append(u)
deg=[len(graph[i]) for i in range(n+1)]
max_deg=max(deg[1:])
most=[i for i in range(1,n+1) if deg[i]==max_deg]
print(*most, max_deg)
hubs=[]
for node in range(1,n+1):
    visited=set([node]); q=deque([node])
    while q:
        cur=q.popleft()
        for nxt in graph[cur]:
            if nxt not in visited: visited.add(nxt); q.append(nxt)
    if len(visited)==n: hubs.append(node)
print(*hubs) if hubs else print('없음')