from collections import deque

N, M, P = map(int,input().split())
s, g = map(int, input().split())
s-=1;g-=1

G = [list() for _ in range(N)]
for i in range(M):
    u, v = map(int, input().split())
    u-=1;v-=1
    G[u].append(v)
    G[v].append(u)

disS = [[-1]*2 for _ in range(N)]
disG = [[-1]*2 for _ in range(N)]
disS[s][0]=0
disG[g][0]=0
d = deque()
d.append((s,0))
while d:
    v, dis = d.popleft()
    for nex in G[v]:
        if disS[nex][(dis+1)%2]==-1:
            disS[nex][(dis+1)%2]=dis+1
            d.append((nex,dis+1))
d.append((g,0))
while d:
    v, dis = d.popleft()
    for nex in G[v]:
        if disG[nex][(dis+1)%2]==-1:
            disG[nex][(dis+1)%2]=dis+1
            d.append((nex,dis+1))

ans = []
for i in range(N):
    if P%2==0:
        if disS[i][0]!=-1 and disG[i][0]!=-1 and disS[i][0]+disG[i][0]<=P:
            ans.append(i+1)
        if disS[i][1]!=-1 and disG[i][1]!=-1 and disS[i][1]+disG[i][1]<=P:
            ans.append(i+1)
    else:
        if disS[i][0]!=-1 and disG[i][1]!=-1 and disS[i][0]+disG[i][1]<=P:
            ans.append(i+1)
        if disS[i][1]!=-1 and disG[i][0]!=-1 and disS[i][1]+disG[i][0]<=P:
            ans.append(i+1)
ans.sort()
if ans:
    print(len(ans))
    print(*ans,sep='\n')
else:
    print(-1)