#include <bits/stdc++.h>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
using namespace std;
#ifdef LOCAL_DEV
	void debug_impl() { std::cerr << std::endl; }
	template<typename Head, typename... Tail> void debug_impl(Head head, Tail... tail) { std::cerr << " " << head << (sizeof...(tail) ? "," : ""); debug_impl(tail...); }
	#define debug(...) std::cerr << std::boolalpha << "(" << #__VA_ARGS__ << ") ="; debug_impl(__VA_ARGS__); std::cerr << std::noboolalpha;
#else
	#define debug(...)
#endif
#ifdef LOCAL_TEST
	#define BOOST_STACKTRACE_USE_ADDR2LINE
	#define BOOST_STACKTRACE_ADDR2LINE_LOCATION /usr/local/opt/binutils/bin/addr2line
	#define _GNU_SOURCE
	#include <boost/stacktrace.hpp>
	template<typename T> class dvector : public std::vector<T> {
	public:
		dvector() : std::vector<T>() {}
		explicit dvector(size_t n, const T& value = T()) : std::vector<T>(n, value) {}
		dvector(const std::vector<T>& v) : std::vector<T>(v) {}
		dvector(const std::initializer_list<T> il) : std::vector<T>(il) {}
		dvector(const typename std::vector<T>::iterator first, const typename std::vector<T>::iterator last) : std::vector<T>(first, last) {}
		dvector(const std::string::iterator first, const std::string::iterator last) : std::vector<T>(first, last) {}
		T& operator[](size_t n) {
			try { return this->at(n); } catch (const std::exception& e) {
				std::cerr << boost::stacktrace::stacktrace() << std::endl; return this->at(n);
			}
		}
		const T& operator[](size_t n) const {
			try { return this->at(n); } catch (const std::exception& e) {
				std::cerr << boost::stacktrace::stacktrace() << std::endl; return this->at(n);
			}
		}
	};
	class dbool {
	private:
		bool boolvalue;
	public:
		dbool() : boolvalue(false) {}
		dbool(bool b) : boolvalue(b) {}
		dbool(const dbool &b) : boolvalue(b.boolvalue) {}
		operator bool&() { return boolvalue; }
		operator const bool&() const { return boolvalue; }
	};
	template<typename T1, typename T2> std::ostream& operator<<(std::ostream& s, const std::pair<T1, T2>& p) { return s << "(" << p.first << ", " << p.second << ")"; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const dvector<T>& v) {
		for (int i = 0, len = v.size(); i < len; ++i){ s << v[i]; if (i < len - 1) s << "\t"; } return s; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const dvector< dvector<T> >& vv) {
		for (int i = 0, len = vv.size(); i < len; ++i){ s << vv[i] << std::endl; } return s; }
	template<typename T1, typename T2> std::ostream& operator<<(std::ostream& s, const std::map<T1, T2>& m) {
		s << "{" << std::endl; for (auto itr = m.begin(); itr != m.end(); ++itr){ s << "\t" << (*itr).first << " : " << (*itr).second << std::endl; } s << "}" << std::endl; return s; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const std::set<T>& se) {
		s << "{ "; for (auto itr = se.begin(); itr != se.end(); ++itr){ s << (*itr) << "\t"; } s << "}" << std::endl; return s; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const std::multiset<T>& se) {
		s << "{ "; for (auto itr = se.begin(); itr != se.end(); ++itr){ s << (*itr) << "\t"; } s << "}" << std::endl; return s; }
	#define vector dvector
	#define bool dbool
#endif
//#define int long long
using ll = long long;
using bll = boost::multiprecision::cpp_int;
using bdouble = boost::multiprecision::cpp_dec_float_100;
//constexpr int INF = 1e9;//INT_MAX=(1<<31)-1=2147483647
constexpr ll INF = (ll)1e18;//(1LL<<63)-1=9223372036854775807
constexpr ll MOD = (ll)1e9 + 7;
constexpr double EPS = 1e-9;
constexpr int dx[4]={1,0,-1,0};
constexpr int dy[4]={0,1,0,-1};
#define p(var) std::cout<<var<<std::endl
#define PI (acos(-1))
#define rep(i, n)   for(ll i=0, i##_length=(n); i< i##_length; ++i)
#define repeq(i, n) for(ll i=1, i##_length=(n); i<=i##_length; ++i)
#define all(v) (v).begin(), (v).end()
#define uniq(v) (v).erase(unique((v).begin(), (v).end()), (v).end());
template<typename T> inline void pv(vector<T> &v) { for(ll i=0, N=v.size(); i<N; i++) std::cout << v[i] << " \n"[i==N-1]; }
template<typename T> inline T gcd(T a, T b) { return b ? gcd(b,a%b) : a; }
template<typename T> inline T lcm(T a, T b) { return a / gcd(a,  b) * b; }
template<typename T1, typename T2> inline T1 power(T1 x, T2 n){ return n ? power(x*x%MOD,n/2)*(n%2?x:1)%MOD : 1; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

/*-----8<-----8<-----*/


void warshall_floyd(vector<vector<ll>> &d) {
	ll N=d.size();
	for (ll k=0; k<N; k++) {
		for (ll i=0; i<N; i++) {
			for (ll j=0; j<N; j++){
				if(d[i][k] != INF && d[k][j] != INF && d[i][k] + d[k][j] < d[i][j]){
					d[i][j] = d[i][k] + d[k][j];
				}
			}
		}
	}
}


void warshall_floyd2(vector<vector<ll>> &d) {
	ll N=d.size();
	for (ll k=0; k<N; k++) {
		for (ll i=0; i<N; i++) {
			for (ll j=0; j<N; j++){
				if(d[i][k] != INF && d[k][j] != INF && d[i][k] + d[k][j] +1 < d[i][j]){
					d[i][j] = d[i][k] + d[k][j] +1;
				}
			}
		}
	}
}

void input() {
	ll N, M, L;

	ll Q;

	scanf("%lld%lld%lld", &N, &M, &L);
	vector<ll> A(M,0),B(M,0),C(M,0);
	rep(i, M) scanf("%lld%lld%lld", &A[i], &B[i], &C[i]);
	scanf("%lld", &Q);
	vector<ll> S(Q,0),T(Q,0);
	rep(i, Q) scanf("%lld%lld", &S[i], &T[i]);



	vector<vector<ll>> d(N, vector<ll>(N, INF));
	for (ll i = 0; i < N; i++) d[i][i] = 0;
	for(ll i=0; i<M; i++) {
		ll from=A[i];
		ll to=B[i];
		ll cost=C[i];
		from--;to--;
		d[from][to] = cost;
		d[to][from] = cost;//無向グラフの場合は両方に辺を張る
	}
	warshall_floyd(d);
	debug(d);



	vector<vector<ll>> d2(N, vector<ll>(N, INF));
	for (ll i = 0; i < N; i++) d[i][i] = 0;
	rep(i,N) for(ll j=i+1; j<N; j++) {
		if(d[i][j]<=L){
			d2[i][j] = 0;
			d2[j][i] = 0;
		}
	}
	warshall_floyd2(d2);

	vector<ll> anslist;
	rep(i,Q){
		ll from=S[i]-1;
		ll to=T[i]-1;
		ll ans=d2[from][to]==INF ? -1 :d2[from][to];
		anslist.push_back(ans);
	}

	debug(ans);
	rep(i,Q)printf("%lld\n", anslist[i]);
}

signed main() {
	input();

	return 0;
}


Measured memory_bytes: 5240