import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

# 同じ距離のときにルートの辞書順が小さい方を選べばいいので
# キーの２番目にルートを文字列でいれておいてワーシャルフロイド
def main():
    inf = 10 ** 9
    n, m, s, g = MI()
    edge = [LI() for _ in range(m)]
    node = [(inf, "")] * n
    node[s] = (0, str(s))
    update = True
    while update:
        update = False
        for u, v, c in edge:
            if node[u] > node[v]: u, v = v, u
            du, ru = node[u]
            dv, rv = node[v]
            if dv > du + c or (dv == du + c and rv > ru + str(v)):
                node[v] = (du + c, ru + str(v))
                update = True

    path = list(node[g][1])
    print(*path)

main()