import heapq

def main():
    import sys
    input = sys.stdin.read().split()
    idx = 0
    N = int(input[idx]); idx +=1
    M = int(input[idx]); idx +=1
    S = int(input[idx]); idx +=1
    G = int(input[idx]); idx +=1
    
    adj = [[] for _ in range(N)]
    for _ in range(M):
        a = int(input[idx]); idx +=1
        b = int(input[idx]); idx +=1
        c = int(input[idx]); idx +=1
        adj[a].append( (b, c) )
        adj[b].append( (a, c) )
    
    INF = float('inf')
    distances = [INF] * N
    distances[S] = 0
    paths = [None] * N
    paths[S] = [S]
    
    heap = []
    heapq.heappush(heap, (0, [S], S))
    
    found = False
    while heap:
        current_dist, current_path, current_node = heapq.heappop(heap)
        if current_node == G:
            print(' '.join(map(str, current_path)))
            found = True
            break
        if current_dist > distances[current_node]:
            continue
        if current_path != paths[current_node]:
            continue
        for neighbor, cost in adj[current_node]:
            new_dist = current_dist + cost
            new_path = current_path + [neighbor]
            if new_dist < distances[neighbor]:
                distances[neighbor] = new_dist
                paths[neighbor] = new_path.copy()
                heapq.heappush(heap, (new_dist, new_path, neighbor))
            elif new_dist == distances[neighbor]:
                if paths[neighbor] is None or new_path < paths[neighbor]:
                    paths[neighbor] = new_path.copy()
                    heapq.heappush(heap, (new_dist, new_path, neighbor))
    if not found:
        pass  # According to the problem statement, a path always exists.

if __name__ == "__main__":
    main()