from collections import defaultdict, deque

INF = 1 << 60
N, M, S, G = map(int, input().split())
adj = defaultdict(list)
for _ in range(M):
    a, b, c = map(int, input().split())
    adj[a].append((b, c))
    adj[b].append((a, c))

dists = [INF] * N
q = deque([(0, G)])  # ゴールから探索する
while q:
    d, v = q.popleft()
    if dists[v] <= d: continue
    dists[v] = d

    for to, cost in adj[v]:
        if dists[to] <= d + cost: continue
        q.append((d+cost, to))

# 経路復元
path = [S]  # スタート地点から復元
while (v := path[-1]) != G:
    nv = INF  # 次の頂点
    for to, cost in adj[v]:
        if dists[to]+cost == dists[v]:
            nv = min(nv, to)

    assert nv != INF
    path.append(nv)

print(*path)