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

#define fs first
#define sc second

const LL MOD = 1e9+7;

template<class T>bool chmax(T &a, const T &b) {
    if (a < b) { a = b; return true; }
    return false;
}
template<class T>bool chmin(T &a, const T &b) {
    if (b < a) { a = b; return true; }
    return false;
}


// std::vector Declaration
template<typename T>
vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) {
    return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

// std::vector Initialization
template<typename T>
void fill_all(T& arr, const T& v) { arr = v; }
template<typename T, typename U>
void fill_all(T& arr, const U& v) { for (auto& i : arr) fill_all(i, v); }

// std::vector Debug
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    os << "[";
    bool a = 1;
    for (auto e : v) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::deque Debug
template<typename T>
ostream& operator<<(ostream& os, const deque<T>& d) {
    os << "[";
    bool a = 1;
    for (auto e : d) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "]";
    return os;
}

// std::pair Debug
template<typename T, typename U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    os << "(" << p.first << " " << p.second << ")";
    return os;
}

// std::set Debug
template<typename T>
ostream& operator<<(ostream& os, const set<T>& st) {
    os << "{";
    bool a = 1;
    for (auto e : st) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "}";
    return os;
}

// std::multiset Debug
template<typename T>
ostream& operator<<(ostream& os, const multiset<T>& st) {
    os << "{";
    bool a = 1;
    for (auto e : st) {
        os << (a ? "" : " ");
        os << e;
        a = 0;
    }
    os << "}";
    return os;
}

// std::map Debug
template<typename T, typename U>
ostream& operator<<(ostream& os, const map<T, U>& mp) {
    os << "{";
    bool a = 1;
    for (auto e : mp) {
        os << (a ? "" : " ");
        os << e.first << ":" << e.second;
        a = 0;
    }
    os << "}";
    return os;
}

// std::tuple Debug
template<int N, class Tuple>
void out(ostream& os, const Tuple& t){}
template<int N, class Tuple, class H, class ...Ts>
void out(ostream& os, const Tuple& t) {
    if (N) os << " ";
    os << get<N>(t);
    out<N+1,Tuple,Ts...>(os, t);
}
template<class ...Ts>
ostream& operator<<(ostream& os, const tuple<Ts...>& t) {
    os << "(";
    out<0,tuple<Ts...>,Ts...>(os, t);
    os << ")";
    return os;
}

// Debug
#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl

template<typename T>
struct edge {
    int src, to;
    T cost;

    edge(int to, T cost) : src(-1), to(to), cost(cost) {}
    edge(int src, int to, T cost) : src(src), to(to), cost(cost) {}

    friend ostream& operator<<(ostream& os, const edge& e) {
        return os << "(" << e.src << "->" << e.to << ":" << e.cost << ")";
    }
};

template<typename T>
using Edges = vector<edge<T>>;
template<typename T>
using WeightedGraph = vector<Edges<T>>;
using UnWeightedGraph = vector<vector<int>>;
template<typename T>
using MatrixGraph = vector<vector<T>>;

template<typename T>
void warshall_floyd(MatrixGraph<T> &g) {
    const auto INF = numeric_limits<T>::max();
    for(int k = 0; k < g.size(); k++) {
        for(int i = 0; i < g.size(); i++) {
            for(int j = 0; j < g.size(); j++) {
                if(g[i][k] == INF || g[k][j] == INF) continue;
                g[i][j] = min(g[i][j], g[i][k] + g[k][j]);
            }
        }
    }
}

int main()
{
    int n, m; cin >> n >> m;
    LL L; cin >> L;
    vector<int> a(m), b(m);
    vector<LL> c(m);
    for (int i = 0; i < m; ++i) {
        cin >> a[i] >> b[i] >> c[i];
        --a[i], --b[i];
    }
    int Q; cin >> Q;
    vector<int> s(Q), t(Q);
    for (int i = 0; i < Q; ++i) {
        cin >> s[i] >> t[i];
        --s[i], --t[i];
    }

    MatrixGraph<LL> G = make_v<LL>(n, n);
    MatrixGraph<int> G2 = make_v<int>(n, n);
    fill_all(G, numeric_limits<LL>::max());
    fill_all(G2, numeric_limits<int>::max());
    for (int i = 0; i < m; ++i) {
        G[a[i]][b[i]] = G[b[i]][a[i]] = c[i];
    }

    warshall_floyd(G);

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            if (G[i][j] <= L) {
                G2[i][j] = 1;
            }
        }
    }

    warshall_floyd(G2);
    for (int i = 0; i < Q; ++i) {
        int cost = G2[s[i]][t[i]];
        cout << (cost == numeric_limits<int>::max() ? -1 : cost-1) << endl;
    }

    return 0;
}


Measured memory_bytes: 2944