#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
inline ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
inline ll lcm(ll a, ll b) { return a / gcd(a, b)*b; }
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T>& V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> >& Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T>& mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }
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...));}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type fill_v(T &t,const V &v){t=v;}
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type fill_v(T &t,const V &v){for(auto &e:t) fill_v(e,v);}
/*
 <url:https://atcoder.jp/contests/abc143/tasks/abc143_e>
 問題文============================================================
 =================================================================
 解説=============================================================
 ================================================================
 */

template<class Type>
Type solve(Type res = Type()){
    int N,M,L; cin >> N >> M >> L;
    vector<vector<pii>> G(N);
    for(int i = 0; i < M;i++){
        int A,B,C; cin >> A >> B >> C;
        A--; B--;
        G[A].push_back(pii(B,C));
        G[B].push_back(pii(A,C));
    }
    
    vector<vector<pii>> dist(N,vector<pii>(N,pii(INF,INF)));
    for(int i = 0; i < N;i++){
        using Item = tuple<int,int,int>;
        priority_queue<Item,vector<Item>,greater<Item>> pq;
        dist[i][i] = pii(0,-L);
        pq.push(Item(0,-L,i));
        while(pq.size()){
            int cnt,leftL,n;
            tie(cnt,leftL,n) = pq.top(); pq.pop();
            leftL = -leftL;

            if(dist[i][n] < pii(cnt,-leftL)) continue;
            
            for(auto e:G[n]){
                int next = e.first;
                int cost = e.second;
                
                int next_cnt = cnt;
                int next_leftL = leftL;
                if(next_leftL >= cost){
                    next_leftL -= cost;
                }else if(L >= cost){
                    next_cnt++;
                    next_leftL = L - cost;
                }else{
                    continue;
                }
                
                if(dist[i][next] > pii(next_cnt,-next_leftL)){
                    dist[i][next] = pii(next_cnt,-next_leftL);
                    pq.push(Item(next_cnt,-next_leftL,next));
                }
            }
            
        }
    }
    
    int Q; cin >> Q;
    while(Q--){
        int s,t; cin >> s >> t;
        s--; t--;
        
        if(dist[s][t].first == INF){
            cout << -1 << endl;
        }else{
            cout << dist[s][t].first << endl;
        }
    }
    return res;
}
int main(void) {
    cin.tie(0); ios_base::sync_with_stdio(false);
    solve(0);
    // cout << fixed << setprecision(15) << solve<ll>() << endl;
    return 0;
}


Measured memory_bytes: 3012