import sys

N,M,P = map(int,input().split())
S,GG = map(int,input().split())
G = [[] for _ in range(N+1)]
for _ in range(M):
    u,v = map(int,input().split())
    G[u].append(v)
    G[v].append(u)
inf = 10 ** 10
ds = [[inf] * 2 for _ in range(N+1)]
dg = [[inf] * 2 for _ in range(N+1)]
ds[S][0] = 0
dg[GG][0] = 0
from collections import deque
q = deque()
q.append((S,0))
while q:
    now,flag = q.popleft()
    for v in G[now]:
        if ds[v][1-flag] == inf:
            ds[v][1-flag] = ds[now][flag] + 1
            q.append((v,1-flag))
q.append((GG,0))
while q:
    now,flag = q.popleft()
    for v in G[now]:
        if dg[v][1-flag] == inf:
            dg[v][1-flag] = dg[now][flag] + 1
            q.append((v,1-flag))

ans = []
if P % 2 == 0:
    for i in range(1,N+1):
        if ds[i][0] + dg[i][0] <= P or ds[i][1] + dg[i][1] <= P:
            ans.append(i)
else:
    for i in range(1,N+1):
        if ds[i][1] + dg[i][0] <= P or ds[i][0] + dg[i][1] <= P:
            ans.append(i)
if len(ans) == 0:
    print(-1)
else:
    print(len(ans))
    print(*ans,sep="\n")