import heapq

def main():
    import sys
    input = sys.stdin.read
    data = input().split()
    idx = 0
    n = int(data[idx]); idx +=1
    m = int(data[idx]); idx +=1
    S = int(data[idx]); idx +=1
    G = int(data[idx]); idx +=1
    
    adj = [[] for _ in range(n)]
    for _ in range(m):
        a = int(data[idx]); idx +=1
        b = int(data[idx]); idx +=1
        c = int(data[idx]); idx +=1
        adj[a].append((b, c))
        adj[b].append((a, c))
    
    INF = float('inf')
    dist = [INF] * n
    prev = [-1] * n
    dist[S] = 0
    heap = []
    heapq.heappush(heap, (0, S))
    
    while heap:
        d_u, u = heapq.heappop(heap)
        if d_u > dist[u]:
            continue
        for v, c in adj[u]:
            new_dist = d_u + c
            if new_dist < dist[v]:
                dist[v] = new_dist
                prev[v] = u
                heapq.heappush(heap, (new_dist, v))
            elif new_dist == dist[v]:
                if prev[v] == -1 or u < prev[v]:
                    prev[v] = u
                    heapq.heappush(heap, (new_dist, v))
    
    # Reconstruct path
    path = []
    current = G
    while current != -1:
        path.append(current)
        current = prev[current]
    path = path[::-1]
    
    print(' '.join(map(str, path)))

if __name__ == "__main__":
    main()