local function meld(node1,node2)
    if not node1 then
        return node2
    elseif not node2 then
        return node1
    elseif node1[1]<node2[1] then
        node2[4]=node1[3]
        node1[3]=node2
        return node1
    else
        node1[4]=node2[3]
        node2[3]=node1
        return node2
    end
end

local function pairing(node,stack)
    if node and node[4] then
        return pairing(node[4][4],rawset(meld(node,node[4]),4,stack))
    else
        return stack,node
    end
end

local function meld_pairs(stack,node)
    if stack then
        return meld_pairs(stack[4],meld(stack,node))
    else
        return node
    end
end

local PairingHeap={}

PairingHeap.empty=function(self)
    return not self[1]
end

PairingHeap.push=function(self,key,value)
    self[1]=meld(self[1],{key,value,false,false})
end

PairingHeap.top=function(self)
    return self[1][2]
end

PairingHeap.pop=function(self)
    self[1]=meld_pairs(pairing(self[1][3],false))
end

PairingHeap.new=function()
    return setmetatable({false},{__index=PairingHeap})
end

----------

local n,m,s,g=io.read("*n","*n","*n","*n")
local graph={}
for i=0,n-1 do
    graph[i]={}
end
for i=1,m do
    local a,b,c=io.read("*n","*n","*n")
    graph[a][b]=c
    graph[b][a]=c
end

local INF=10^20
local dist={}
local prev={}
for i=0,n-1 do
    dist[i]=INF
    prev[i]=PairingHeap:new()
end
local pq=PairingHeap:new()
dist[g]=0
pq:push(0,{0,g})

while not pq:empty() do
    local p=pq:top() pq:pop()
    local from=p[2]
    if dist[from]<p[1] then
        goto continue
    end
    for to,cost in pairs(graph[from]) do
        if dist[to]>dist[from]+cost then
            dist[to]=dist[from]+cost
            prev[to]=PairingHeap:new()
            prev[to]:push(from,from)
            pq:push(dist[to],{dist[to],to})
        elseif dist[to]==dist[from]+cost then
            prev[to]:push(from,from)
        end
    end
    ::continue::
end

local path={s}
while path[#path]~=g do
    local cur=path[#path]
    local next=prev[cur]:top()
    table.insert(path,next)
end
print(table.concat(path," "))