from collections import defaultdict
from heapq import heapify, heappop, heappush

n, m, s, g = map(int, input().split())
G = defaultdict(list)
for _ in range(m):
    a, b, c = map(int, input().split())
    G[a].append((b, c))
    G[b].append((a, c))
for i in range(n):
    G[i].sort(key=lambda x: x[0])
INF = 10**18
DP = [INF for _ in range(n)]
DP[s] = 0
H = [(0, s)]
while H:
    cc, cp = heappop(H)
    if cc > DP[cp]:
        continue
    if cp == g:
        break
    for np, dc in G[cp]:
        nc = cc + dc
        if nc >= DP[np]:
            continue
        DP[np] = nc
        heappush(H, (nc, np))
ANS = [g]
res = DP[g]
while ANS[-1] != s:
    cp = ANS[-1]
    for np, dc in G[cp]:
        nc = res - dc
        if nc == DP[np]:
            ANS.append(np)
            res -= dc
            break
ANS.reverse()
print(*ANS)