from collections import deque
INF = 1<<64
N,M,S,T = map(int,input().split())
G = [[] for _ in range(N)]
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()
cost = [INF] * N
cost[T] = 0
Queue = deque()
Queue.append(T)
while Queue:
    pos = Queue.popleft()
    for nxt,c in G[pos]:
        if cost[pos] + c < cost[nxt]:
            cost[nxt] = cost[pos] + c
            Queue.append(nxt)
pos = S
ans = [S]
while pos != T:
    for nxt,c in G[pos]:
        if cost[pos] - c == cost[nxt]:
            ans.append(nxt)
            pos = nxt
            break
print(*ans)