import heapq

def read_data():
    N, M, S, G = map(int, input().split())
    Es = [dict() for i in range(N)]
    for m in range(M):
        a, b, c = map(int, input().split())
        Es[a][b] = c
        Es[b][a] = c
    return N, M, S, G, Es

def solve(N, M, start, goal, Es):
    dist = [float('inf')] * N
    path = [tuple() for n in range(N)]
    dist[start] = 0
    path[start] = (start, )
    pq = [(0, path[start])]
    while pq:
        d, pathi = heapq.heappop(pq)
        v = pathi[-1]
        if v == goal:
            return pathi
        for u, nd in Es[v].items():
            new_d = d + nd
            if (new_d < dist[u]) or (new_d == dist[u] and pathi + (u, ) < path[u]):
                dist[u] = new_d
                path[u] = pathi + (u, )
                heapq.heappush(pq, (new_d, path[u]))

if __name__ == '__main__':
    param = read_data()
    path = solve(*param)
    print(*path)