#include<iostream>
#include<string>
#include<algorithm>
#include<cstdlib>
#include<cmath>
#include<vector>
#include<list>
#include<cstdint>
#include<bits/stdc++.h>
#include<queue>
#include<set>

#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rep_r(i, n) for(int i = n-1; i >= 0; i--)
#define rep1(i, n) for(int i = 1; i <= (int)(n); i++)
#define REP(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define all(x) (x).begin(),(x).end()
#define SZ(x) ((ll)(x).size())
#define bit(n) (1LL<<(n))
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() );

#define INF bit(60)
#define pb push_back
#define mod 1000000007

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

using namespace std;
using uif=uint_fast64_t;
using ll=long long int;

int qp(int a,ll b){int ans=1;do{if(b&1)ans=1ll*ans*a%mod;a=1ll*a*a%mod;}while(b>>=1);return ans;}
int qp(int a,ll b,int mo){int ans=1;do{if(b&1)ans=1ll*ans*a%mo;a=1ll*a*a%mo;}while(b>>=1);return ans;}

int gcd(int a,int b){return b?gcd(b,a%b):a;}
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};


#define FACSIZE 2002

ll invfac[FACSIZE];
ll fac[FACSIZE];

ll mod_pow(ll ,ll );
ll mod_add(ll ,ll );
ll mod_mul(ll ,ll );
ll mod_div(ll ,ll );
void make_fact(ll );
void make_invfact(ll );



int main(void){

  ll n,m,l;
  cin>>n>>m>>l;
  vector<ll> a(m);
  vector<ll> b(m);
  vector<ll> c(m);

  vector<vector<ll>> v(n+1,vector<ll>());
  vector<vector<ll>> e(n+1,vector<ll>(n+1,INT_MAX));

  rep1(i,n) e[i][i]=0;
  e[0][0]=INT_MAX;

  rep(i,m){
    cin>>a[i]>>b[i]>>c[i];
    v[a[i]].push_back(b[i]);
    v[b[i]].push_back(a[i]);
    e[a[i]][b[i]]=c[i];
    e[b[i]][a[i]]=c[i];
  }
  ll q;
  cin>>q;
  vector<ll> s(q);
  vector<ll> t(q);
  rep(i,q) cin>>s[i]>>t[i];
  
  vector<vector<ll>> min_length(n+1,vector<ll>(n+1,INT_MAX));
  vector<vector<ll>> min_cnt(n+1,vector<ll>(n+1,INT_MAX));
  rep1(i,n) min_cnt[i][i]=0;
  min_cnt[0][0]=INT_MAX;
  vector<vector<ll>> e_l(n+1,vector<ll>(n+1,0));
  //vector<vector<pair<ll,ll>>> dp(n+1,vector<pair<ll,ll>>(n+1,make_pair(INT_MAX,0)));

  //priority_queue< pa , vector< pa > ,decltype(ff) > p_que(ff);
  rep1(i,n){
    rep1(j,n){
        min_length[i][j]=e[i][j];
    }
  }

  rep1(k,n){
    rep1(i,n){
      rep1(j,n){
        if(min_length[i][j]>min_length[i][k]+min_length[k][j]) min_length[i][j]=min_length[i][k]+min_length[k][j];
      }
    }
  }

  rep1(i,n){
    rep1(j,n){
        if( min_length[i][j]<=l ) min_cnt[i][j]=1;
    }
  }

  rep1(k,n){
    rep1(i,n){
      rep1(j,n){
        if(min_cnt[i][j]>min_cnt[i][k]+min_cnt[k][j]) min_cnt[i][j]=min_cnt[i][k]+min_cnt[k][j];
      }
    }
  }

  /*
  rep1(i,n){
    rep1(j,n){
      cout << min_length[i][j] << " ";
    }
    cout <<endl;
  }
  */
  /*
  rep1(i,n){
    rep1(j,n){
      cout << min_cnt[i][j] << " ";
    }
    cout <<endl;
  }
  //*/

  /*
  for(auto v:dp){
    for(auto x:v){
      cout << "(" << x.first << "," << x.second << ")"  << " ";
    }
    cout << endl;
  }
  //*/
  rep(i,q){
    auto ans=min_cnt[s[i]][t[i]];
    if(ans>=INT_MAX){
      cout << -1 << endl;
    }
    else{
      cout << ans-1 << endl;
    }
  }

  return 0;

}

ll mod_pow(ll x,ll r){
  if(r==0) return 1;
  else if(r==1) return x%mod;
  else if(r%2==0){
    ll t=mod_pow(x,r/2)%mod;
    return t*t %mod;
  } 
  else{
    ll t=mod_pow(x,r/2)%mod;
    ll k= t*t %mod;
    return k*x%mod;
  } 
}
ll mod_add(ll a,ll b){
  return (a+b)%mod;
}

ll mod_mul(ll a,ll b){
  return (a*b)%mod;
}

ll mod_div(ll a,ll b){
  return mod_mul(a,mod_pow(b,mod-2));
}

void make_fact(ll n){
  fac[0]=1;
  rep(i,n){
    fac[i+1]=mod_mul(fac[i],i+1);
  }  
}

void make_invfact(ll n){
  invfac[n]= mod_pow( fac[n] ,mod-2);
  for(int i=n-1;i>=0;i--){
    invfac[i]=mod_mul(invfac[i+1],i+1);
  }

}


Measured memory_bytes: 7040