#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define SPEED ios_base::sync_with_stdio(false); cin.tie(NULL);
#define FOR(i, a, b) for (ll i = a; i < b; ++i)
#define RFOR(i, b, a) for (ll i = b; i >= a; --i)
#define ALL(x) x.begin(), x.end()
#define DEBUG(args...) { string _s = #args; replace(ALL(_s), ' ', '\0');\
replace(ALL(_s), ',', ' ');\
stringstream _ss(_s); istream_iterator<string> _it(_ss); _debug(_it, args);}
#define endl "\n"
#define F first
#define S second
#define pb(x) push_back(x)
#define mp(x, y) make_pair(x, y)
#define int ll
using namespace std;
using namespace __gnu_pbds;

template<typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

void _debug(istream_iterator<string>) {}
template<typename T, typename... Args>
void _debug(istream_iterator<string> it, T first, Args... args) {
    cerr << ">> " << *it << " : " << first << endl; _debug(++it, args...);
}
template <typename T1, typename T2>
inline ostream& operator << (ostream& out, const pair<T1, T2>& p) {
    return out << "(" << p.F << ", " << p.S << ")";
}
template<typename T>
inline ostream& operator << (ostream& out, const vector<T>& v) {
    if (v.empty()) return out << "[]";
    else { out << '['; for (auto& e : v) { out << e << ", "; } return out << "\b\b]"; }
}
template<typename T>
inline ostream& operator << (ostream& out, const set<T>& s) {
    if (s.empty()) return out << "{}";
    else { out << '{'; for (auto& e : s) { out << e << ", "; } return out << "\b\b}"; }
}
template<typename T>
inline ostream& operator << (ostream& out, const unordered_set<T>& s) {
    return out << set<T>(ALL(s));
}
template<typename T1, typename T2>
inline ostream& operator << (ostream& out, const map<T1, T2>& m) {
    if (m.empty()) return out << "{}";
    out << '{'; for (auto& p : m) { out << p << ", "; } return out << "\b\b}";
}
template<typename T1, typename T2>
inline ostream& operator << (ostream& out, const unordered_map<T1, T2>& m) {
    return out << map<T1, T2>(ALL(m));
}
template<typename T>
inline ostream& operator << (ostream& out, const ordered_set<T>& s) {
    return out << set<T>(ALL(s));
}

typedef long long ll;
typedef long double ld;
typedef vector<long long> vll;
typedef pair<ll, ll> pll;
typedef vector<pair<ll, ll>> vpll;
typedef unordered_map<ll, ll> STll;
/************************************** MAIN PROGRAM ********************************************/
const int MAX = 301;
const ll INF = 1e18;
vector<pair<int, ll>> adj[MAX];
//vector<pair<int, ll>> adjNew[MAX];
int n, m;
ll l;

ll dp[MAX][MAX][MAX];
ll dist[MAX][MAX];

void runFloydOnNew() {
    FOR(i, 0, MAX) FOR(j, 0, MAX) FOR(k, 0, MAX) dp[i][j][k] = INF;
    FOR(k, 0, n + 1) {
        FOR(i, 0, n) {
            FOR(j, 0, n) {
                if (k == 0) {
                    dp[i][j][k] = dist[i][j];
                } else {
                    dp[i][j][k] = min({dp[i][j][k - 1], dp[i][k - 1][k - 1] + dp[k - 1][j][k - 1], INF});
                }
            }
        }
    }
}


void runFloydOnOld() {
    FOR(i, 0, MAX) FOR(j, 0, MAX) FOR(k, 0, MAX) dp[i][j][k] = INF;
    FOR(k, 0, n + 1) {
        FOR(i, 0, n) {
            FOR(j, 0, n) {
                if (k == 0) {
                    dp[i][j][k] = dist[i][j];
                }
                else dp[i][j][k] = min({dp[i][j][k - 1], dp[i][k - 1][k - 1] + dp[k - 1][j][k - 1], INF});
            }
        }
    }
} 

main()
{
    //freopen("input.txt", "r", stdin);
    SPEED
    cin >> n >> m >> l;
    FOR(i, 0, n) {
        FOR(j, 0, n) {
            dist[i][j] = INF;
        }
//        dist[i][i] = 0;
    }
    
    FOR(i, 0, m) {
        int u, v;
        ll weight;
        cin >> u >> v >> weight;
        u--, v--;
        adj[u].push_back({v, weight});
        adj[v].push_back({u, weight});
        dist[u][v] = dist[v][u] = weight;
    }
    runFloydOnOld();
    
    FOR(i, 0, n) {
        FOR(j, 0, n) {
          //  DEBUG(dp[i][j][n])
            dist[i][j] = dp[i][j][n] <= l ? 1 : INF;
        }
//        dist[i][i] = 0;
    }
    
    runFloydOnNew();
    int q;
    cin >> q;
    FOR(_, 0, q) {
        int v, w;
        cin >> v >> w;
        v--, w--;
        ll ans = dp[v][w][n] >= INF ? -1 : dp[v][w][n] - 1;
        cout << ans << endl;
    }
    //DEBUG(adjNew[0], adjNew[1], adjNew[2])
}
/************************************** END OF PROGRAM ******************************************/
/** Stuff you should look for:
 * int overflow, array bounds, over-counting, graph is not a tree/connected
 * special cases (n=1?), set/unordered_set TLE, multi-set/set error
 * do something instead of nothing and stay organized
 */


Measured memory_bytes: 216704