from heapq import *

def dijkstra(start, goal):
    D[start] = 0
    q = []
    heappush(q, (0, start))

    while len(q) > 0:
        d, u = heappop(q)
        if u == goal:
            return
        if d > D[u]: continue
        for v, c in E[u]:
            if D[v] == D[u] + c:
                if P[v] > u:
                    P[v] = u
            if D[v] > D[u] + c:
                D[v] = D[u] + c
                heappush(q, (D[v], v))
                P[v] = u
    return []

N,M,S,G = map(int,input().split())
ABC = [list(map(int,input().split())) for _ in range(M)]
E = [[] for _ in range(N + 1)]
for a, b, c in ABC:
    E[a].append([b, c])
    E[b].append([a, c])
INF = 10 ** 7
D = [INF] * (N + 1)
P = [-1] * (N + 1)

dijkstra(S, G)
now = G
ans = [G]
while now != S:
    now = P[now]
    ans.append(now)

ans = reversed(ans)
print(*ans)