import heapq
import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
inf = 10**9

N, M, S, G = map(int, input().split())
edge = [[] for _ in range(N)]
for _ in range(M):
    a, b, c = map(int, input().split())
    edge[a].append((b, c))
    edge[b].append((a, c))

dist = [inf] * N
prev = [N] * N
dist[S] = 0
que = [(0, S)]
while que:
    ds, s = heapq.heappop(que)
    if dist[s] < ds:
        continue
    for t, dt in edge[s]:
        if dist[t] > ds + dt:
            dist[t] = ds + dt
            heapq.heappush(que, (ds + dt, t))
            prev[t] = s
        elif dist[t] == ds + dt:
            if prev[t] > s:
                prev[t] = s
                heapq.heappush(que, (ds + dt, t))

ans = []
now = G
while now < N:
    ans.append(now)
    now = prev[now]
ans.reverse()
print(*ans)