#include<bits/stdc++.h>
#define int long long
using namespace std;
const int mn=505,mm=180005;
int n,m,l,qq;
int hd[mn],to[mm<<1],nxt[mm<<1],w[mm<<1],cnt=2;
void add(int x,int y,int z)
{
    nxt[cnt]=hd[x];
    to[cnt]=y;
    w[cnt]=z;
    hd[x]=cnt++;
}
int a[mn][mn],jy[mn][mn];
int vis[mn];
struct sta
{
    int a,jy,u;
}tmp;
struct cmp
{
    bool operator()(sta x,sta y)
    {
        if(x.jy!=y.jy)return x.jy>y.jy;
        return x.a<y.a;
    }
};
priority_queue<sta,vector<sta>,cmp> q;
void dijkstra(int s)
{
    // vis[s]=s;
    a[s][s]=l;
    jy[s][s]=0;
    q.push({l,0,s});
    while(!q.empty())
    {
        tmp=q.top();
        q.pop();
        if(vis[tmp.u]==s)continue;
        vis[tmp.u]=s;
        // cerr<<tmp.u<<" "<<tmp.a<<" "<<tmp.jy<<"-------------\n";
        for(int i=hd[tmp.u];i;i=nxt[i])
        {
            int u=to[i];
            if(vis[u]==s)continue;
            if(a[s][tmp.u]<w[i])
            {
                if(jy[s][tmp.u]+1<jy[s][u] || (jy[s][tmp.u]+1==jy[s][u] && l-w[i]>a[s][u]))
                {
                    jy[s][u]=jy[s][tmp.u]+1;
                    a[s][u]=l-w[i];
                    q.push({a[s][u],jy[s][u],u});
                    // cerr<<a[s][u]<<" "<<jy[s][u]<<" sss "<<u<<"\n";
                }
            }
            else
            {
                if(jy[s][tmp.u]<jy[s][u] || (jy[s][tmp.u]==jy[s][u] && a[s][tmp.u]-w[i]>a[s][u]))
                {
                    jy[s][u]=jy[s][tmp.u];
                    a[s][u]=a[s][tmp.u]-w[i];
                    q.push({a[s][u],jy[s][u],u});
                    // cerr<<a[s][u]<<" "<<jy[s][u]<<" ddd "<<u<<"\n";
                }
            }
        }
    }
}
signed main()
{
    // memset(a,0x3f,sizeof(a));
    memset(jy,0x3f,sizeof(jy));
    int x,y,z;
    scanf("%lld%lld%lld",&n,&m,&l);
    for(int i=1;i<=m;i++)
    {
        scanf("%lld%lld%lld",&x,&y,&z);
        if(z>l)continue;
        add(x,y,z);
        add(y,x,z);
    }
    
    for(int i=1;i<=n;i++)dijkstra(i);
    scanf("%lld",&qq);
    while(qq--)
    {
        scanf("%lld%lld",&x,&y);
        if(jy[x][y]==0x3f3f3f3f3f3f3f3f)printf("-1\n");
        else printf("%lld\n",jy[x][y]);
    }
}