import sys

import math

sys.setrecursionlimit(10 ** 5)

from typing import List, Tuple


def int1(x: str, /): return int(x) - 1


def input(): return sys.stdin.readline().rstrip('\n')


def dbg(*args, **kwargs):
    print(*(repr(arg) for arg in args), *(f'{k}: {repr(v)}' for k, v in kwargs.items()), sep='; ', file=sys.stderr)


def main():
    n, m, s, g = map(int, input().split())
    e = [[math.inf] * n for _ in range(n)]
    d = [[math.inf] * n for _ in range(n)]
    for i in range(n): d[i][i] = 0
    for _ in range(m):
        a, b, c = map(int, input().split())
        d[a][b] = e[a][b] = d[b][a] = e[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])

    cur = s
    ans = []
    while cur != g:
        ans.append(cur)
        for i in range(n):
            if e[cur][i] + d[i][g] == d[cur][g]:
                cur = i
                break

    return ans + [g]


def _start():
    ret = main()

    if ret is not None:
        if isinstance(ret, List) or isinstance(ret, Tuple):
            print(*ret)
        else:
            print(ret)


if __name__ == '__main__':
    _start()