import sys
input = sys.stdin.readline
from collections import deque


def bfs(G, s, N):
    Q = deque([])
    inf = 10 ** 18
    dist = [inf] * N
    par = [-1] * N
    dist[s] = 0
    for u in G[s]:
        par[u] = s
        dist[u] = 1
        Q.append(u)

    while Q:
        u = Q.popleft()
        for v in G[u]:
            if dist[v] != inf:
                continue
            dist[v] = dist[u] + 1
            par[v] = u
            Q.append(v)
            
    return dist


N, M, P = map(int, input().split())
s, g = map(int, input().split())
s, g = s - 1, g - 1
G = [[] for i in range(2 * N)]
for i in range(M):
    u, v = map(int, input().split())
    u, v = u - 1, v - 1
    G[u].append(v + N)
    G[v].append(u + N)
    G[u + N].append(v)
    G[v + N].append(u)
    
ans = []
DS = bfs(G, s, 2 * N)
DG = bfs(G, g, 2 * N)

for i in range(N):
    if P % 2:
        if DS[i] + DG[i + N] <= P or DS[i + N] + DG[i] <= P:
            ans.append(i + 1)
    else:
        if DS[i] + DG[i] <= P or DS[i + N] + DG[i + N] <= P:
            ans.append(i + 1)

if ans:
    print(len(ans))
    for a in ans:
        print(a)
else:
    print(-1)