#pragma region
 
#include <bits/stdc++.h>
using namespace std;
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define POW2(n) (1LL << (n))
#define FOR(i, begin, end) for (register int i = (begin); i < (end); i++)
#define IFOR(i, begin, end) for (register int i = (end)-1; i >= (begin); i--)
#define REP(i, n) FOR(i, 0, n)
#define IREP(i, n) IFOR(i, 0, n)
#define MOD 1000000007
#define debug(x) cerr << #x << " = " << (x) << " (line: " << __LINE__ << ") " << endl;
typedef long long ll;
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
  for (auto &v : vec) is >> v;
  return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
  os << "vec[ ";
  REP(i, vec.size())
  i == 0
      ? os << vec[i]
      : os << ", " << vec[i];
  os << " ]";
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const deque<T> &deq) {
  os << "deq[ ";
  REP(i, deq.size())
  i == 0
      ? os << deq[i]
      : os << ", " << deq[i];
  os << " ]";
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &set) {
  os << "{ ";
  for (auto &&s : set) &s == &(*set.begin()) ? os << s : os << ", " << s;
  os << " }";
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &set) {
  os << "{ ";
  for (auto &&s : set) &s == &(*set.begin()) ? os << s : os << ", " << s;
  os << " }";
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const multiset<T> &set) {
  os << "{ ";
  for (auto &&s : set) &s == &(*set.begin()) ? os << s : os << ", " << s;
  os << " }";
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const unordered_multiset<T> &set) {
  os << "{ ";
  for (auto &&s : set) &s == &(*set.begin()) ? os << s : os << ", " << s;
  os << " }";
  return os;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
template <typename TK, typename TV>
ostream &operator<<(ostream &os, const map<TK, TV> &m) {
  os << "{ ";
  for (auto &&k : m) &k == &(*m.begin()) ? os << k.first << " => " << k.second : os << ", " << k.first << " => " << k.second;
  os << " }";
  return os;
}
template <typename TK, typename TV>
ostream &operator<<(ostream &os, const unordered_map<TK, TV> &m) {
  os << "{ ";
  for (auto &&k : m) &k == &(*m.begin()) ? os << k.first << " => " << k.second : os << ", " << k.first << " => " << k.second;
  os << " }";
  return os;
}
 
#pragma endregion
#define MAX 2147483647
 
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(16);
 
  int N, M, L;
  cin >> N >> M >> L;
  vector<vector<ll>> map(N + 1, vector<ll>(N + 1, MAX));
  REP(i, M) {
    int a, b, c;
    cin >> a >> b >> c;
    map[a][b] = c;
    map[b][a] = c;
  }
  FOR(i, 1, N + 1)
  map[i][i] = 0;
  int Q;
  cin >> Q;
  vector<int> s(Q), t(Q);
  REP(i, Q)
  cin >> s[i] >> t[i];
 
  FOR(i, 1, N + 1)
  FOR(j, 1, N + 1)
  FOR(k, 1, N + 1) {
    map[j][k] = min(map[j][k], map[j][i] + map[i][k]);
  }
 
  FOR(i, 1, N + 1)
  FOR(j, 1, N + 1) {
    map[i][j] = map[i][j] <= L ? 1 : MAX;
  }
 
  FOR(i, 1, N + 1)
  FOR(j, 1, N + 1)
  FOR(k, 1, N + 1) {
    map[j][k] = min(map[j][k], map[j][i] + map[i][k]);
  }
 
  REP(i, Q) {
    int S = min(s[i], t[i]), T = max(s[i], t[i]);
    cout << (map[S][T] == MAX ? -1 : map[S][T] - 1) << "\n";
  }
}

Measured memory_bytes: 1920