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*/

#include <bits/stdc++.h>
using namespace std;

using VI = vector<int>;
using VVI = vector<VI>;
using PII = pair<int, int>;
using LL = long long;
using VL = vector<LL>;
using VVL = vector<VL>;
using PLL = pair<LL, LL>;
using VS = vector<string>;

#define ALL(a)  begin((a)),end((a))
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define MT make_tuple
#define SZ(a) int((a).size())
#define SORT(c) sort(ALL((c)))
#define RSORT(c) sort(RALL((c)))
#define UNIQ(c) (c).erase(unique(ALL((c))), end((c)))

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

#define FF first
#define SS second

template<class S, class T>
istream& operator>>(istream& is, pair<S,T>& p){
  return is >> p.FF >> p.SS;
}
template<class T>
istream& operator>>(istream& is, vector<T>& xs){
  for(auto& x: xs)
	is >> x;
  return is;
}
template<class S, class T>
ostream& operator<<(ostream& os, const pair<S,T>& p){
  return os << p.FF << " " << p.SS;
}
template<class T>
ostream& operator<<(ostream& os, const vector<T>& xs){
  for(unsigned int i=0;i<xs.size();++i)
	os << (i?" ":"") << xs[i];
  return os;
}
template<class T>
void maxi(T& x, T y){
  if(x < y) x = y;
}
template<class T>
void mini(T& x, T y){
  if(x > y) x = y;
}
void debug(istringstream&){}
template <char sep=',', class Head, class... Tail>
void debug(istringstream& iss, Head&& head, Tail&&... tail)
{
  string name;
  getline(iss, name, ',');
  cout << sep << name << "=" << head;
  debug(iss, forward<Tail>(tail)...);
}

#ifdef PYONPOI
#define DEBUG(...) \
  do{ \
    istringstream ss(#__VA_ARGS__); \
    debug<' '>(ss, __VA_ARGS__); \
    cout<<endl; \
  }while(0)
#else
#define DEBUG
#endif
void init_io(int argc, char* argv[]){
  cin.tie(0);
  ios_base::sync_with_stdio(false);
#ifdef PYONPOI
  if(argc > 1) {
    ifstream *ifs = new ifstream();
    ifs->open(argv[1]);
    cin.rdbuf(ifs->rdbuf());
  }
#endif
}


const double EPS = 1e-10;
const double PI  = acos(-1.0);
const LL MOD = 1e9+7;
const LL INF = 1e15;

PLL dp[310][310];
using Graph = vector<vector<PLL>>;

void dijkstra(Graph& G, int s, int N, LL L){
  REP(i, N) dp[s][i] = MP(INF, INF);
  using State = pair<PLL,int>;
  priority_queue<State,vector<State>,greater<State>> pq;

  pq.push(MP(MP(0, 0), s));
  dp[s][s] = MP(0, 0);
  while(!pq.empty()){
    auto p = pq.top();
    pq.pop();
    PLL dist = p.FF;
    int u = p.SS;

    if(dp[s][u] != dist) continue;
    for(auto e : G[u]){
      int to = e.FF;
      LL w = e.SS;
      if(w > L) continue;

      PLL ns = dist;      
      if(ns.SS + w > L) ns = MP(dist.FF + 1, w);
      else ns.SS += w;

      if(dp[s][to] > ns){
        dp[s][to] = ns;
        pq.push(MP(ns, to));
      }
    }
  }
}

int main(int argc, char* argv[]){
  init_io(argc, argv);

  LL N, M, L;
  cin >> N >> M >> L;

  Graph G(N);
  REP(i,M){
    LL a, b, c;
    cin >> a >> b >> c;
    --a;
    --b;
    G[a].EB(b, c);
    G[b].EB(a, c);
  }

  REP(i,N) dijkstra(G, i, N, L);

  int Q;
  cin >> Q;
  while(Q--){
    int s, t;
    cin >> s >> t;
    LL ans = dp[s-1][t-1].FF;
    if(ans == INF) ans = -1;
    cout << ans << endl;
  }

  return 0;
}


Measured memory_bytes: 4352