import sys
import math
import bisect
from heapq import heapify, heappop, heappush
from collections import deque, defaultdict, Counter
from functools import lru_cache
from itertools import accumulate, combinations, permutations, product

sys.setrecursionlimit(1000000)
MOD = 10 ** 9 + 7
MOD99 = 998244353

input = lambda: sys.stdin.readline().strip()
NI = lambda: int(input())
NMI = lambda: map(int, input().split())
NLI = lambda: list(NMI())
SI = lambda: input()
SMI = lambda: input().split()
SLI = lambda: list(SMI())
EI = lambda m: [NLI() for _ in range(m)]


def adjlist(n, edges, directed=False, in_origin=1):
    if len(edges) == 0:
        return [[] for _ in range(n)]

    weighted = True if len(edges[0]) > 2 else False
    if in_origin == 1:
        if weighted:
            edges = [[x-1, y-1, w] for x, y, w in edges]
        else:
            edges = [[x-1, y-1] for x, y in edges]

    res = [[] for _ in range(n)]

    if weighted:
        for u, v, c in edges:
            res[u].append([v, c])
            if not directed:
                res[v].append([u, c])

    else:
        for u, v in edges:
            res[u].append(v)
            if not directed:
                res[v].append(u)

    return res


def main():
    N, M, S, G = NMI()
    ABC = EI(M)
    Graph = adjlist(N, ABC, in_origin=0)
    INF = 10**10
    D = [[INF]*N for _ in range(N)]
    for i in range(N):
        D[i][i] = 0
    for a, b, c in ABC:
        D[a][b] = c
        D[b][a] = c
    for k in range(N):
        for i in range(N):
            for j in range(N):
                D[i][j] = min(D[i][j], D[i][k] + D[k][j])

    total = D[S][G]
    ans = [S]
    while ans[-1] != G:
        now = ans[-1]
        for b, c in sorted(Graph[now]):
            if c + D[b][G] == total:
                total -= c
                ans.append(b)
                break
    print(*ans)


if __name__ == "__main__":
    main()