#include <cassert>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
//#include <boost/foreach.hpp>
//#include <boost/range/algorithm.hpp>
//#include <boost/multiprecision/cpp_int.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
//#define INF 1e9
#define LINF (1LL<<40)
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define int long long
#define umap unordered_map 
#define re0 return 0
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};
// int dx[]={0,1,0,-1};
// int dy[]={1,0,-1,0};
//typedef pair<int,int> P;

const long long MOD=1000000007LL;
bool isupper(char c){if('A'<=c&&c<='Z')return 1;return 0;}
bool islower(char c){if('a'<=c&&c<='z')return 1;return 0;}
bool iskaibun(string s){for(int i=0;i<s.size()/2;i++)if(s[i]!=s[s.size()-i-1])return 0;return 1;}
bool isnumber(char c){return ('0'<=c&&c<='9');}
bool isalpha(char c){return (isupper(c)||islower(c));}

template<typename T> 
void print(vector<T> v){
    for(int i=0;i<v.size();i++){
        if(i)cout<<" ";
        cout<<v[i];
    }
    cout<<endl;
}
int INF=1e18;

template<typename T>
void printendl(vector<T> v){
    for(auto date:v)cout<<date<<endl;
}

template<typename T>
void printvv(vector<vector<T>> v){
    for(int i=0;i<v.size();i++){
        for(int j=0;j<v[i].size();j++){
            if(j)cout<<" ";
            cout<<v[i][j];
        }
        cout<<endl;
    }
}
struct P{
    int x,y;
};

int gcd(int a,int b){
    if(b==0)return a;
    else return gcd(b,a%b);
}

signed main(){
    int n,m,l;
    cin>>n>>m>>l;
    vector<vector<int>> v(n,vector<int>(n,INF));
    rep(i,0,n)v[i][i]=0;
    rep(i,0,m){
        int a,b,c;
        scanf("%lld %lld %lld",&a,&b,&c);
        a--; b--;
        v[a][b]=c;
        v[b][a]=c;
    }

    rep(i,0,n){
        rep(j,0,n){
            rep(k,0,n){
                v[j][k]=min(v[j][k],v[j][i]+v[i][k]);
            }
        }
    }

    vector<vector<int>> dis(n,vector<int>(n,INF));
    rep(i,0,n){
        rep(j,0,n){
            if(j==i)continue;
            if(v[i][j]<=l)dis[i][j]=1;
        }
    }

    rep(i,0,n){
        rep(j,0,n){
            rep(k,0,n){
                dis[j][k]=min(dis[j][k],dis[j][i]+dis[i][k]);
            }
        }
    }
    int q;cin>>q;
    rep(i,0,q){
        int to,from;
        scanf("%lld %lld",&to,&from);
        to--;
        from--;
        if(dis[to][from]==INF){
            cout<<-1<<endl;
        }else {
            cout<<dis[to][from]-1<<endl;
        }
    }
    
    
    
    
}

/*
*/

Measured memory_bytes: 1920