#include <bits/stdc++.h>
#define LLI long long int
#define FOR(v, a, b) for(LLI v = (a); v < (b); ++v)
#define FORE(v, a, b) for(LLI v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(LLI v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define popcount __builtin_popcount
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <misc/C++/Debug.cpp>
#else
#define dump(...) ((void)0)
#endif

#define gcd __gcd

using namespace std;
template <class T> constexpr T lcm(T m, T n){return m/gcd(m,n)*n;}

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}

template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}

struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
  }
}init;

template <typename Cost = int> class Edge{
public:
  int from,to;
  Cost cost;
  Edge() {}
  Edge(int to, Cost cost): to(to), cost(cost){}
  Edge(int from, int to, Cost cost): from(from), to(to), cost(cost){}

  Edge rev() const {return Edge(to,from,cost);}
  
  friend ostream& operator<<(ostream &os, const Edge &e){
    os << "(FROM: " << e.from << "," << "TO: " << e.to << "," << "COST: " << e.cost << ")";
    return os;
  }
};

template <typename T> using Graph = vector<vector<Edge<T>>>;
template <typename T> using Tree = vector<vector<Edge<T>>>;

template <typename C, typename T> void add_edge(C &g, int from, int to, T w){
  g[from].push_back(Edge<T>(from, to, w));  
}

template <typename C, typename T> void add_undirected(C &g, int a, int b, T w){
  g[a].push_back(Edge<T>(a, b, w));
  g[b].push_back(Edge<T>(b, a, w));
}


template <typename T>
struct WarshallFloyd{
  int n;
  vector<vector<T>> dist;
  vector<vector<bool>> no_path;
  bool has_negative_cycle;
  
  WarshallFloyd(const Graph<T> &graph):
    n(graph.size()), dist(n, vector<T>(n)), no_path(n, vector<bool>(n, true)), has_negative_cycle(false)
  {

    REP(i,n){
      dist[i][i] = 0;
      no_path[i][i] = false;
    }
  
    REP(i,n){
      for(auto &e : graph[i]){
        dist[e.from][e.to] = e.cost;
        no_path[e.from][e.to] = false;
      }
    }
  
    REP(k,n){
      REP(i,n){
        REP(j,n){
          if(not no_path[i][k] and not no_path[k][j]){
            if(no_path[i][j]){
              no_path[i][j] = false;
              dist[i][j] = dist[i][k]+dist[k][j];
            }else{
              dist[i][j] = min(dist[i][j], dist[i][k]+dist[k][j]);
            }
          }
        }
      }
    }

    REP(i,n) if(dist[i][i] < 0) has_negative_cycle = true;
  }
};




int main(){
  int N,M,L;
  while(cin >> N >> M >> L){
    Graph<LLI> g(N);
    REP(i,M){
      int a,b; cin >> a >> b;
      --a, --b;
      LLI c; cin >> c;
      if(c <= L){
        add_undirected(g, a, b, c);
      }
    }

    WarshallFloyd<LLI> res(g);

    Graph<int> g2(N);

    REP(i,N){
      REP(j,N){
        if(i < j and not res.no_path[i][j]){
          if(res.dist[i][j] <= L){
            add_undirected(g2, i, j, 1);
          }
        }
      }
    }

    
    WarshallFloyd<int> res2(g2);
    

    int Q; cin >> Q;

    REP(i,Q){
      int s,t; cin >> s >> t;
      --s, --t;

      if(res2.no_path[s][t]){
        cout << -1 << endl;
      }else{
        //dump(s,t,res.dist[s][t]);
        /*
        if(res2.dist[s][t] % L == 0){
          cout << res.dist[s][t] / L - 1 << endl;
        }else{
          cout << res.dist[s][t] / L << endl;
          }*/
        cout << res2.dist[s][t] - 1 << endl;
      }
      
      
    }
  }

  return 0;
}


Measured memory_bytes: 5760