from heapq import *

n, m, s, g = map(int, input().split())

edges = [[] for _ in range(n)]
for _ in range(m):
    u, v, c = map(int, input().split())
    edges[u].append((v, c))
    edges[v].append((u, c))

dist = [1 << 30] * n
dist[g] = 0
nex = [-1] * n
hq = [g]
while hq:
    tmp = heappop(hq)
    d = tmp // n
    pos = tmp - d * n
    if dist[pos] < d:
        continue
    for npos, c in edges[pos]:
        tmp = c + d
        if tmp < dist[npos]:
            dist[npos] = tmp
            heappush(hq, tmp * n + npos)
            nex[npos] = pos
        elif tmp == dist[npos] and pos < nex[npos]:
            nex[npos] = pos
ans = []
while s != -1:
    ans.append(s)
    s = nex[s]
print(*ans)