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

template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
    return '"' + s + '"';
}

string to_string(const char* s) {
    return to_string((string) s);
}

string to_string(bool b) {
     return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
    bool first = true;
    string res = "{";
    for (int i = 0; i < static_cast<int>(v.size()); i++) {
        if (!first) {
            res += ", ";
        }
        first = false;
        res += to_string(v[i]);
    }
    res += "}";
    return res;
}

template <size_t N>
string to_string(bitset<N> v) {
    string res = "";
    for (size_t i = 0; i < N; i++) {
        res += static_cast<char>('0' + v[i]);
    }
    return res;
}

template <typename A>
string to_string(A v) {
    bool first = true;
    string res = "{";
    for (const auto &x : v) {
        if (!first) {
            res += ", ";
        }
            first = false;
            res += to_string(x);
    }
    res += "}";
    return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
    return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
    return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
    return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << " " << to_string(H);
    debug_out(T...);
}
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

#define rep(i,n) for (int i = 0; i < n; ++i)
#define reps(i,s,n) for (int i = s; i < n; ++i)
#define rep1(i,n) for (int i = 1; i <= n; ++i)
#define per(i,n) for (int i = n - 1; i >= 0; --i)
#define per1(i,n) for (int i = n; i >= 1; --i)
#define all(c) begin(c),end(c)
template<typename T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
void chmax(string &a, string b) {
    if (a == "-") a = b;
    else if (a.size() < b.size()) a = b;
    else if (a.size() == b.size()) {
        if (a < b) a = b;
    }
}
template<typename T> inline T intceil(T a, T b) { return (a + (b - 1)) / b; }
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
typedef tuple<int,int,int> Tint;
typedef pair<ll,ll> PL;
const long long MOD = 1e9+7;
#define precout() cout << std::fixed << std::setprecision(20);
#define print(a) cout << a << endl;
template<typename T> void printv(vector<T>&v) {
    int n = v.size() - 1;
    rep(i, n) cout << v[i] << " ";
    cout << v.back() << endl;
}
typedef complex<ld> cd;
static const long double pi = acos(-1.0);
const string alphabet = "abcdefghijklmnopqrstuvwxyz";
const int dy[4] = { 0, 1, 0, -1 };
const int dx[4] = { 1, 0, -1, 0 };
// if(nextH >= 0 && nextH < H && nextW >= 0 && nextW < W)

struct AdjacencyGraph {
    vector<vector<long long>> g;
    int n;
    long long inf = 1e15;

    AdjacencyGraph(int initN) {
        n = initN;
        g = vector<vector<long long>>(n, vector<long long>(n, inf));
    }

    void insertDirectedEdge(int from, int to, long long weight) {
        chmin(g[from][to], weight);
    }

    void insertUndirectedEdge(int a, int b, long long weight) {
        insertDirectedEdge(a, b, weight);
        insertDirectedEdge(b, a, weight);
    }

    vector<vector<ll>> warshallFloyd() {
        vector<vector<ll>> dist = g;
        rep(k, n) {
            rep(i, n) {
                rep(j, n) {
                    if(i == j) continue;
                    chmin(dist[i][j], dist[i][k] + dist[k][j]);
                }
            }
        }
        return dist;
    }
};

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N,M; cin >> N >> M;
    ll L; cin >> L;
    AdjacencyGraph fuelG(N);
    rep(i, M) {
        int a,b,c; cin >> a >> b >> c;
        --a, --b;
        fuelG.insertUndirectedEdge(a, b, c);
    }

    auto fuelDist = fuelG.warshallFloyd();

    AdjacencyGraph lessLG(N);
    rep(i, N) {
        rep(j, N) {
            if(i == j) continue;
            if(fuelDist[i][j] <= L) {
                lessLG.insertUndirectedEdge(i, j, 1);
            }
        }
    }

    auto ansDist = lessLG.warshallFloyd();

    int Q; cin >> Q;
    vector<ll> ans;
    rep(i, Q) {
        int a,b; cin >> a >> b; --a, --b;
        ans.push_back(ansDist[a][b] >= 1e14 ? -1 : ansDist[a][b] - 1);
    }
    for(auto&a:ans) {
        print(a);
    }
}


Measured memory_bytes: 7128