import heapq
n,m,S,G=map(int,input().split())
g=[[] for _ in range(n)]
for _ in range(m):
    a,b,c=map(int,input().split())
    g[a].append((b,c))
    g[b].append((a,c))
dst=[10**18]*n
cfm=[False]*n
pre=[None]*n
q=[]
heapq.heappush(q,(0,G,-1))
while q:
    now_d,now_place,pre_place=heapq.heappop(q)
    if cfm[now_place]:
        continue
    pre[now_place]=pre_place
    cfm[now_place]=True
    dst[now_place]=now_d
    for to_place,cost in g[now_place]:
        if cfm[to_place]:
            continue
        if dst[to_place]<=now_d+cost:
            continue
        dst[to_place]=now_d+cost
        heapq.heappush(q,(now_d+cost,to_place,now_place))
now=S;ans=[]
while now!=G:
    tmp=10**18
    ans.append(now)
    for to,cost in g[now]:
        if dst[to]+cost==dst[now]:
            tmp=min(tmp,to)
    now=tmp
ans.append(G)
print(*ans)