import sequtils,strutils

proc `<`(A, B : openarray[int]) : bool=
    var
        i : int
    while true:
        if A[i] < B[i]:
            return false
        elif A[i] > B[i]:
            return true
        else:
            i += 1
proc `<=`(A, B : openarray[int]) : bool =
    return A < B
    
type
    priorityQue[I:static[int];T:tuple] = array[I + 1,T]
    item = tuple[id : int; cost : seq[int]]
    dist = tuple[s, d : int]
proc push[T](A:var priorityQue; b: T;)=
    const key = 1
    A[0][0] += 1
    A[A[0][0]] = b # A[0][0]はsize、最大のIndex
    var index = A[0][0]
    while index > 1 and A[index][key] > A[index div 2][key]:
        (A[index],A[index div 2]) = (A[index div 2],A[index])
        index = index div 2
proc pop(A: var priorityQue):item = 
    const key = 1
    result = A[1]
    A[1] = A[A[0][0]]
    var a : item
    A[A[0][0]] = a
    A[0][0] -= 1
    var index = 1
    while index * 2 <= A[0][0]:
        if index * 2 + 1<= A[0][0]:
            if A[index][key] < A[index * 2][key] and A[index * 2 + 1][key] <= A[index * 2][key]:
                (A[index],A[index * 2]) = (A[index * 2],A[index])
                index = index * 2
            elif A[index][key] < A[index * 2 + 1][key]:
                (A[index],A[index * 2 + 1]) = (A[index * 2 + 1],A[index])
                index = index * 2 + 1
            else:
                break
        elif index * 2 <= A[0][0]:
            if A[index][key] < A[index * 2][key]:
                (A[index],A[index * 2]) = (A[index * 2],A[index])
            break
        else:
            break
proc size(A : priorityQue):int=
    return A[0][0]
    
var
    N,M,S,G : int
    a,b,c : int
    
(N, M, S, G) = stdin.readline.split.map(parseInt)
var hyou = newSeqWith(N + 1, newSeq[dist](0))

for m in 1..M:
    (a, b, c) = stdin.readline.split.map(parseInt)
    hyou[a].add((b, c))
    hyou[b].add((a, c))
    
var
    pq : priorityque[400000,item]
    t : item
    mincos : array[201, seq[int]]

for i in 0..200:
    mincos[i] = @[int.high]
block tansaku:
    pq.push((S, @[0, S]))
    while pq.size > 0:
        t = pq.pop
        var c = t.cost[0]
        if t.id == G:
            echo t.cost[1..t.cost.high].join(" ")
            break tansaku
        for p in hyou[t.id]:
            var q = t
            q.cost[0] += p.d
            q.cost.add(p.s)
            if (q.cost < mincos[p.s]) == false:
                mincos[p.s] = q.cost
                q.id = p.s
                pq.push(q)