local mfl, mce, mmi = math.floor, math.ceil, math.min
local SegTree = {}
SegTree.updateAll = function(self)
  for i = self.stagenum - 1, 1, -1 do
    for j = 1, self.cnt[i] do
      self.stage[i][j] = self.func(self.stage[i + 1][j * 2 - 1], self.stage[i + 1][j * 2])
    end
  end
end
SegTree.create = function(self, n, func, emptyvalue)
  self.func, self.emptyvalue = func, emptyvalue
  local stagenum, mul = 1, 1
  self.cnt, self.stage, self.size = {1}, {{}}, {}
  while mul < n do
    mul, stagenum = mul * 2, stagenum + 1
    self.cnt[stagenum], self.stage[stagenum] = mul, {}
  end
  for i = 1, stagenum do self.size[i] = self.cnt[stagenum + 1 - i] end
  self.stagenum = stagenum
  -- for i = 1, #ary do self.stage[stagenum][i] = ary[i] end
  -- for i = #ary + 1, mul do self.stage[stagenum][i] = emptyvalue end
  for i = 1, mul do self.stage[stagenum][i] = emptyvalue end
  self:updateAll()
end
SegTree.getRange = function(self, left, right)
  if left == right then return self.stage[self.stagenum][left] end
  local start_stage = 1
  while right - left + 1 < self.size[start_stage] do
    start_stage = start_stage + 1
  end
  local ret = self.emptyvalue
  local t1, t2, t3 = {start_stage}, {left}, {right}
  while 0 < #t1 do
    local stage, l, r = t1[#t1], t2[#t1], t3[#t1]
    table.remove(t1) table.remove(t2) table.remove(t3)
    local sz = self.size[stage]
    if (l - 1) % sz ~= 0 then
      local newr = mmi(r, mce((l - 1) / sz) * sz)
      table.insert(t1, stage + 1) table.insert(t2, l) table.insert(t3, newr)
      l = newr + 1
    end
    if sz <= r + 1 - l then
      ret = self.func(ret, self.stage[stage][mce(l / sz)])
      l = l + sz
    end
    if l <= r then
      table.insert(t1, stage + 1) table.insert(t2, l) table.insert(t3, r)
    end
  end
  return ret
end
SegTree.setValue = function(self, idx, value, silent)
  self.stage[self.stagenum][idx] = value
  if not silent then
    for i = self.stagenum - 1, 1, -1 do
      local dst = mce(idx / 2)
      local rem = dst * 4 - 1 - idx
      self.stage[i][dst] = self.func(self.stage[i + 1][idx], self.stage[i + 1][rem])
      idx = dst
    end
  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, l = 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")
  if c <= l then
    edge[a][b] = c
    edge[b][a] = c
  end
end
local tanklen = {}
local remlen = {}
local reallen = {}
local inf = 301 * 1000000000
for i = 1, n do
  tanklen[i] = 301
  remlen[i] = 0
  reallen[i] = inf
end
local function lessthan(x, y, cost)
  return reallen[x] + cost < reallen[y]
end
local function merge(x, y)
  if n < x then return y end
  if n < y then return x end
  return lessthan(x, y, 0) and x or y
end
local st = SegTree.new(n, merge, n + 1)
for i = 1, n do st:setValue(i, i) end
local alllen = {}
local function solve(start_pos)
  alllen[start_pos] = {}
  local asked = {}
  for i = 1, n do
    asked[i] = false
    tanklen[i] = 301
    remlen[i] = l
    reallen[i] = inf
  end
  tanklen[start_pos] = 0
  reallen[start_pos] = 0
  st:updateAll()
  for _u = 1, n do
    local src = st.stage[1][1]
    asked[src] = true
    alllen[start_pos][src] = tanklen[src]
    for dst, cost in pairs(edge[src]) do
      if not asked[dst] and lessthan(src, dst, cost) then
        reallen[dst] = reallen[src] + cost
        tanklen[dst] = tanklen[src]
        remlen[dst] = remlen[src] - cost
        if remlen[dst] < 0 then
          tanklen[dst] = tanklen[dst] + 1
          remlen[dst] = l - cost
        end
        st:setValue(dst, dst)
      end
    end
    reallen[src] = inf
    st:setValue(src, src)
  end
end

for i = 1, n do
  solve(i)
end

local q = io.read("*n")
for i = 1, q do
  local s, t = io.read("*n", "*n")
  print(alllen[s][t] < 301 and alllen[s][t] or -1)
end
