import sys,collections,heapq
from collections import deque
sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N,M,P = MI()
S,G = MI()

Graph = [[[] for _ in range(2)] for _ in range(N+1)]
for _ in range(M):
    u,v = MI()
    Graph[u][0].append((v,1))
    Graph[v][0].append((u,1))
    Graph[u][1].append((v,0))
    Graph[v][1].append((u,0))

inf = 10**18
dist_S = [[inf]*2 for _ in range(N+1)]
dist_G = [[inf]*2 for _ in range(N+1)]
dist_S[S][0] = 0
dist_G[G][0] = 0
deq_S = deque([(S,0)])
deq_G = deque([(G,0)])
while deq_S:
    u,r = deq_S.pop()
    for v,s in Graph[u][r]:
        if dist_S[v][s] == inf:
            dist_S[v][s] = dist_S[u][r]+1
            deq_S.appendleft((v,s))
while deq_G:
    u,r = deq_G.pop()
    for v,s in Graph[u][r]:
        if dist_G[v][s] == inf:
            dist_G[v][s] = dist_G[u][r]+1
            deq_G.appendleft((v,s))

ANS = []
for i in range(1,N+1):
    if P % 2 == 0:
        d0 = dist_S[i][0]+dist_G[i][0]
        d1 = dist_S[i][1]+dist_G[i][1]
        if (d0 != inf and d0 <= P) or (d1 != inf and d1 <= P):
            ANS.append(i)
    else:
        d0 = dist_S[i][0]+dist_G[i][1]
        d1 = dist_S[i][1]+dist_G[i][0]
        if (d0 != inf and d0 <= P) or (d1 != inf and d1 <= P):
            ANS.append(i)

if ANS:
    print(len(ANS))
    print(*ANS,sep='\n')
else:
    print(-1)

# DijkstraだとTLE