from heapq import heappop,heappush

N,M,S,G=map(int,input().split())
E=[[] for i in range(N+1)]

for i in range(M):
    a,b,c=map(int,input().split())
    E[a].append((b,c))
    E[b].append((a,c))
    
D=[1<<30]*(N+1)
FROM=[-1]*(N+1)
D[S]=0
Q=[]
Q.append((0,S))

while Q:
    time,now=heappop(Q)

    if D[now]!=time:
        continue

    for to,cost in E[now]:
        if D[to]>time+cost:
            D[to]=time+cost
            heappush(Q,(D[to],to))
            FROM[to]=now
        elif D[to]==time+cost:
            FROM[to]=min(FROM[to],now)
        
now=G
ANS=[G]
while now!=S:
    now=FROM[now]
    ANS.append(now)

print(*ANS[::-1])