import heapq

INF = 1 << 60

n, m, src, dst = map(int, input().split())
g = [[] for _ in range(n)]
for _ in range(m):
  a, b, c = map(int, input().split())
  g[a].append((b, c))
  g[b].append((a, c))

for u in range(n):
  g[u].sort(key=lambda x: x[0])

dist = [INF for _ in range(n)]
dist[dst] = 0
hp = [(dist[dst], dst)]
par = [None for _ in range(n)]
while len(hp) > 0:
  cd, cur = heapq.heappop(hp)
  if cd > dist[cur]:
    continue
  for nxt, c in g[cur]:
    if dist[cur] + c < dist[nxt]:
      par[nxt] = cur
      dist[nxt] = dist[cur] + c
      heapq.heappush(hp, (dist[nxt], nxt))

cur = src
ans = []
while True:
  ans.append(str(cur))
  if cur == dst:
    break
  nxt = None
  for v, c in g[cur]:
    if dist[v] + c == dist[cur]:
      nxt = v
      break
  cur = nxt

print(' '.join(ans))