#ifdef _DEBUG
#define _GLIBCXX_DEBUG
#endif
#define _CRT_SECURE_NO_WARNINGS
#include <ext/pb_ds/assoc_container.hpp>
#include <bits/stdc++.h>

using namespace __gnu_pbds;
using namespace std;

typedef long long ll;
typedef vector<ll> vll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef long double ld;
typedef tree<pair<ll, int>, null_type, less<pair<ll, int>>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

#define mk make_pair
#define inb push_back
#define enb emplace_back
#define X first
#define Y second
#define all(v) v.begin(), v.end()
#define sqr(x) (x) * (x)
#define TIME 1.0 * clock() / CLOCKS_PER_SEC
#define y1 AYDARBOG
//continue break pop_back return

int solve();

int main()
{
    //ios_base::sync_with_stdio(0);
    //cin.tie(0);
#define TASK "treedp"
#ifndef _DEBUG
    //freopen(TASK".in", "r", stdin), freopen(TASK".out", "w", stdout);
#endif
    solve();
#ifdef _DEBUG
    fprintf(stderr, "\nTIME: %.3f\n", TIME);
#endif
}

const int INF = 2e9 + 7;
const ll LINF = 1e18;

const int BUFSZ = (int)1e6 + 7;
char buf[BUFSZ];
string get_str()
{
    scanf(" %s", buf);
    return string(buf);
}

struct edge
{
    int a, b, cst;
    edge() {};
    edge(int a, int b, int cst) : a(a), b(b), cst(cst) {};
    bool operator< (edge x) const
    {
        if (cst == x.cst)
        {
            if (a == x.a)
            {
                return b < x.b;
            }
            return a < x.a;
        }
        return cst < x.cst;
    }
    void print()
    {
        printf("FROM: %d TO: %d T: %d\n", a + 1, b + 1, cst);
    }
};

int solve()
{
    int n, m, d;
    scanf("%d %d %d", &n, &m, &d);
    vector<set<edge>> G(n);
    for (int i = 0; i < m; ++i)
    {
        edge e;
        scanf("%d %d %d", &e.a, &e.b, &e.cst);
        --e.a, --e.b;
        G[e.a].insert(e);
        swap(e.a, e.b);
        G[e.a].insert(e);
    }
    int q;
    scanf("%d", &q);
    while (q--)
    {
        int s, f;
        scanf("%d %d", &s, &f);
        --s, --f;
        if (s == f)
        {
            puts("0");
            continue;
        }
        int ans = INF;
        queue<edge> q;
        queue<int> dd;
        vector<set<edge>> g = G;
        for (auto x : g[s])
        {
            q.push(x);
            dd.push(1);
        }
        g[s].clear();
        while (!q.empty())
        {
            edge cur = q.front();
            int cdst = dd.front();
            dd.pop();
            //printf("CURDST: %d CUR: ", cdst);
            //cur.print();
            q.pop();
            int u = cur.b;
            if (u == f)
            {
                ans = min(ans, cdst);
            }
            int t = cur.cst;
            for (auto x : g[u])
            {
                if (abs(x.cst - t) > d)
                    continue;
                //x.print();
                q.push(x);
                dd.push(cdst + 1);
            }
            for (auto it = g[u].begin(); it != g[u].end();)
            {
                if (abs((*it).cst - t) > d)
                {
                    ++it;
                }
                else
                {
                    auto it1 = it;
                    ++it;
                    g[u].erase(*it1);
                }
            }
        }
        if (ans == INF)
            puts("-1");
        else
            printf("%d\n", ans);
    }
    return 0;
}