n,m,p=map(int,input().split())
s,t=map(int,input().split())
uv=[list(map(int,input().split())) for _ in range(m)]
g=[[] for _ in range(n)]
for u,v in uv:
  u,v=u-1,v-1
  g[u].append(v)
  g[v].append(u)
s,t=s-1,t-1
inf=float('inf')
fromsev=[inf]*n
fromtev=[inf]*n
fromsod=[inf]*n
fromtod=[inf]*n
from collections import deque
todo=deque([[s,0]])
fromsev[s]=0
while todo:
  v,d=todo.popleft()
  for nv in g[v]:
    if (d+1)%2==0:
      if fromsev[nv]>d+1:
        fromsev[nv]=d+1
        todo.append([nv,d+1])
    else:
      if fromsod[nv]>d+1:
        fromsod[nv]=d+1
        todo.append([nv,d+1])
todo=deque([[t,0]])
fromtev[t]=0
while todo:
  v,d=todo.popleft()
  for nv in g[v]:
    if (d+1)%2==0:
      if fromtev[nv]>d+1:
        fromtev[nv]=d+1
        todo.append([nv,d+1])
    else:
      if fromtod[nv]>d+1:
        fromtod[nv]=d+1
        todo.append([nv,d+1])
ans=[]
if p%2==0:
  for i in range(n):
    if fromsev[i]+fromtev[i]<=p:
      ans.append(i+1)
    elif fromsod[i]+fromtod[i]<=p:
      ans.append(i+1)
else:
  for i in range(n):
    if fromsev[i]+fromtod[i]<=p:
      ans.append(i+1)
    elif fromsod[i]+fromtev[i]<=p:
      ans.append(i+1)
if ans:
  print(len(ans))
  print(*ans,sep='\n')
else:
  print(-1)