import heapq

def main():
    n, m, S, G = map(int, input().split())
    adj = [[] for _ in range(n)]
    for _ in range(m):
        a, b, c = map(int, input().split())
        adj[a].append((b, c))
        adj[b].append((a, c))
    
    dist = [float('inf')] * n
    path = [tuple() for _ in range(n)]
    dist[S] = 0
    path[S] = (S,)
    
    heap = []
    heapq.heappush(heap, (0, path[S]))
    
    while heap:
        current_cost, current_path = heapq.heappop(heap)
        u = current_path[-1]
        if u == G:
            print(' '.join(map(str, current_path)))
            return
        if current_cost > dist[u]:
            continue
        for v, c in adj[u]:
            new_cost = current_cost + c
            new_path = current_path + (v,)
            if new_cost < dist[v]:
                dist[v] = new_cost
                path[v] = new_path
                heapq.heappush(heap, (new_cost, new_path))
            elif new_cost == dist[v] and new_path < path[v]:
                path[v] = new_path
                heapq.heappush(heap, (new_cost, new_path))

if __name__ == "__main__":
    main()