import sys
from heapq import heappush, heappop

inf = 1<<30

def solve():
    N, M, S, G = map(int, input().split())
    Adj = [[] for i in range(N)]

    for i in range(M):
        ai, bi, ci = map(int, input().split())
        Adj[ai].append((bi, ci))
        Adj[bi].append((ai, ci))

    d, p = dijkstra(N, Adj, S)

    keiro = [G]

    while p[G] != G:
        keiro.append(p[G])
        G = p[G]

    keiro.reverse()

    print(*keiro)

def dijkstra(N, Adj, s):
    d = [inf] * N
    p = [inf] * N
    visited = [False] * N
    d[s] = 0
    p[s] = s
    pq = [(0, s)]

    for i in range(N - 1):
        while pq:
            di, v = heappop(pq)

            if not visited[v] and di == d[v]:
                break

        visited[v] = True

        for u, c in Adj[v]:
            if d[v] + c < d[u]:
                d[u] = d[v] + c
                p[u] = v
                heappush(pq, (d[u], u))
            elif d[v] + c == d[u] and v < p[u]:
                p[u] = v

    return d, p

if __name__ == '__main__':
    solve()