local mfl, mce = math.floor, math.ceil
local mmi, mma = math.min, math.max
local pow2 = {1}
for i = 2, 28 do pow2[i] = pow2[i - 1] * 2 end
local SegTree = {}
SegTree.updateAll = function(self)
  for i = self.stagenum - 1, 1, -1 do
    local cnt = pow2[i]
    for j = 0, cnt - 1 do
      self.stage[cnt + j] = self.func(self.stage[(cnt + j) * 2], self.stage[(cnt + j) * 2 + 1])
    end
  end
end
SegTree.create = function(self, n, func, emptyvalue)
  self.func, self.emptyvalue = func, emptyvalue
  local stagenum, mul = 1, 1
  self.stage = {} -- use 1D Tree (stage[], not stage[][])
  while mul < n do
    mul, stagenum = mul * 2, stagenum + 1
  end
  self.stagenum = stagenum
  for i = 1, mul * 2 - 1 do self.stage[i] = emptyvalue end
  for i = 1, n do self.stage[mul + i - 1] = i end
  self:updateAll()
end
SegTree.update = function(self, idx, force)
  idx = idx + pow2[self.stagenum] - 1
  for i = self.stagenum - 1, 1, -1 do
    local dst = mfl(idx / 2)
    local rem = dst * 4 + 1 - idx
    self.stage[dst] = self.func(self.stage[idx], self.stage[rem])
    if not force and self.stage[dst] ~= self.stage[idx] then break end
    idx = dst
  end
end
SegTree.new = function(n, func, emptyvalue)
  local obj = {}
  setmetatable(obj, {__index = SegTree})
  obj:create(n, func, emptyvalue)
  return obj
end

local n, m = io.read("*n", "*n")
local p, q, t = io.read("*n", "*n", "*n")
local edge = {}
for i = 1, n do
  edge[i] = {}
end
for i = 1, m do
  local a, b, c = io.read("*n", "*n", "*n")
  edge[a][b], edge[b][a] = c, c
end

local inf = 1000000007 * 2000

local function getlen(spos)
  local len = {}
  local asked = {}
  for i = 1, n do
    len[i] = inf
    asked[i] = false
  end
  len[spos] = 0
  asked[n + 1] = true

  local function mergefunc(x, y)
    if asked[x] then return y
    elseif asked[y] then return x
    else
      return len[x] < len[y] and x or y
    end
  end

  local st = SegTree.new(n, mergefunc, n + 1)

  for i = 1, n do
    local src = st.stage[1]
    if asked[src] then break end
    if inf <= len[src] then break end
    asked[src] = true
    st:update(src, true)
    for dst, cost in pairs(edge[src]) do
      if len[src] + cost < len[dst] then
        len[dst] = len[src] + cost
        st:update(dst)
      end
    end
  end
  return len
end

local len_1 = getlen(1)
local len_p = getlen(p)
local len_q = getlen(q)

if len_1[p] + len_1[q] + len_p[q] <= t then
  print(t) os.exit()
end

local ret = -1
for i = 1, n do
  local lenpq = mma(len_p[i], len_q[i])
  local z = 2 * (len_1[i] + lenpq)
  if z <= t then
    if ret < t - 2 * lenpq then
      ret = t - 2 * lenpq
    end
  end
end
print(ret)