#Created on 2015/03/16 ans
inf = 10 ** 9

[N,M,S,G] = map(int, input().split())

dist = [[inf] * N for _ in range(N)]
edge = [[0] * N for _ in range(N)]

for i in range(N) : dist[i][i] = 0

for _ in range(M) :
    a,b,c = map(int, input().split())
    dist[a][b] = dist[b][a] = c
    edge[a][b] = edge[b][a] = c
    
for k in range(N) :
    for i in range(N) :
        for j in range(N) :
            dist[i][j] = min(dist[i][j], dist[i][k]+dist[k][j])
            

ans = str(S)
while S != G :
    for i in range(N) :
        if edge[S][i] + dist[i][G] == dist[S][G] and edge[S][i] :
            ans += " " + str(i)
            S = i
            break
        
print(ans)