INF = 1e18
from heapq import heappush, heappop
def main():
    N, M, S, T = map(int, input().split())
    G = [list() for _ in range(N)]
    for i in range(M):
        u, v, w = map(int, input().split())
        G[u].append((v, w))
        G[v].append((u, w))

    # T --> S に最短距離
    kakutei = [False] * (N)
    prev = [N]*N
    dist = [INF] * (N)
    dist[T] = 0
    prev[T] = -1
    que = []
    heappush(que, (0, -1, T))
    while que:
        curr_dist, pre, pos = heappop(que)
        if kakutei[pos]:
            continue
        kakutei[pos] = True
        prev[pos] = pre
        for nex, kyori in G[pos]:
            if kakutei[nex]:
                continue
            if dist[nex] >= curr_dist + kyori:
                dist[nex] = curr_dist + kyori
                heappush(que, (dist[nex], pos, nex))
    ans = []
    pos = S
    while pos != -1:
        ans.append(pos)
        pos = prev[pos]
    print(*ans)

if __name__ == "__main__":
    main()