#include <bits/stdc++.h>
#include <boost/algorithm/string/join.hpp>
#include <boost/range/irange.hpp>
#include <boost/multiprecision/cpp_int.hpp>
using namespace std;
using boost::irange;
using boost::algorithm::join;

typedef long long ll;
typedef unsigned long long ull;
//typedef long double ld;

typedef map<int, int> mii;
typedef pair<int, int> pii;
typedef pair<double,double> pdd;
typedef set<int> si;
typedef set<ll> sll;
typedef vector<int> vi;
typedef vector<pair<int, int > > vii;
typedef vector<ll> vll;
typedef vector<double> vd;
typedef vector<vi> vvi;
typedef vector<vii> vvii;
typedef vector<vll> vvll;

constexpr ll MOD = 1e9+7;
template<typename T>constexpr auto inf=numeric_limits<T>::max()/4;
constexpr int INF=inf<int>;
constexpr ll LINF=inf<ll>;

#define Sort(x) sort(begin(x),end(x))
#define Reverse(x) reverse(begin(x),end(x))
#define ABS(a,b) ((a)<(b)?(b)-(a):(a)-(b))
#define nbit(n) (1ull<<(n))
#define _ol3(_1,_2,_3,name,...)name
#define _rep(i,n)_repi(i,0,n)
#define _repi(i,a,b)for(int i=a,i##_l=(b);i<i##_l;++i)
#define REP(...) _ol3(__VA_ARGS__,_repi,_rep,)(__VA_ARGS__)
#define REPR(i,n) for(int i=n-1;i>=0;--i)
#define REPA(i,v) REP(i,(v).size())

// sort(begin(x), end(x), greater<ll>());
// lower_bound(a.begin(), a.end(), val): a[i] ≥ valである最左の位置
// upper_bound(a.begin(), a.end(), val): a[i] > valである最左の位置

// Returns minimum of a and b.
// If a is less b, a is set to b.
template<typename T>
T chmin(T& a, T b) {
  if (a > b) {
    a = b;
  }
  return a;
}

// Returns maximum of a and b.
// If a is less b, a is set to b.
template<typename T>
T chmax(T& a, T b) {
  if (a < b) {
    a = b;
  }
  return a;
}

template <typename T>
void dumpContents(const T& v, const string& msg)
{
  cerr << "### " << msg << " ###\n";
  for (const auto& x : v) {
    cerr << x << " ";
  }
  cerr << endl;
}

struct before_main_function {
  before_main_function() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout<<setprecision(20)<<fixed;
    #define endl "\n"
  }
} before_main_function;

// ========== end of template ==========
constexpr int N_MAX=300;
int N, M;
ll L;
vi A, B;
vll C;

ll D[N_MAX][N_MAX];
int H[N_MAX][N_MAX];

void createH() {
  REP(i, N-1) {
    for (int j=i+1; j<N; j++) {
      if (D[i][j] <= L) {
        H[i][j] = 1;
        H[j][i] = 1;
      }
    }
  }
}

void solve(int s, int t) {
}

int main(int argc, char** argv) {
  cin >> N >> M >> L;

  REP(i, N_MAX) {
    REP(j, N_MAX) {
      D[i][j] = i==j ? 0 : LINF;
      H[i][j] = i==j ? 0 : INF;
    }
  }

  A.resize(M);
  B.resize(M);
  C.resize(M);
  REP(i, M) {
    int a, b;
    ll c;
    cin >> a >> b >> c;
    a--; b--;
    A[i] = a;
    B[i] = b;
    C[i] = c;

    D[a][b] = c;
    D[b][a] = c;

    if (c<=L) {
      H[a][b] = 1;
      H[b][a] = 1;
    }
  }

  // warshall floyd
  REP(k, N) {
    REP(i, N) {
      REP(j, N) {
        D[i][j] = min({D[i][j], D[i][k]+D[k][j]});
      }
    }
  }

//REP(i,N) {
//  REP(j, N) {
//cerr << D[i][j] << " ";
//  }
//  cerr << endl;
//}

  createH();

  // warshall floyd
  REP(k, N) {
    REP(i, N) {
      REP(j, N) {
        H[i][j] = min({H[i][j], H[i][k]+H[k][j]});
      }
    }
  }

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

    int ret = H[s][t];
    if (ret < INF) {
      cout << ret-1 << endl;
    } else {
      cout << -1 << endl;
    }
  }

  return 0;
}


Measured memory_bytes: 2176