#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#define ll long long
using namespace std;
const int MN=305;
ll n,m,l,q,d[MN][MN],e[MN][MN];
void write(ll n){if(n<0){putchar('-');write(-n);return;}if(n>9)write(n/10);putchar(n%10+'0');}
ll read(){ll x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}return x*f;}
int main(){
    memset(d,63,sizeof(d));memset(e,63,sizeof(e));
    n=read();m=read();l=read();
    for(int i=1; i<=m; i++){
        ll u=read(),v=read(),w=read();
        d[u][v]=min(d[u][v],w);
        d[v][u]=min(d[v][u],w);
    }
    for(int k=1; k<=n; k++) for(int i=1; i<=n; i++) for(int j=1; j<=n; j++) d[i][j]=min(d[i][j],d[i][k]+d[k][j]);
    for(int i=1; i<=n; i++) for(int j=1; j<=n; j++) if(d[i][j]<=l) e[i][j]=1;
    for(int k=1; k<=n; k++) for(int i=1; i<=n; i++) for(int j=1; j<=n; j++) e[i][j]=min(e[i][j],e[i][k]+e[k][j]);
    q=read();while(q--){
        ll u=read(),v=read();
        if(u==v) write(0),putchar('\n');
        else if(e[u][v]>1e9) write(-1),putchar('\n');
        else write(e[u][v]-1),putchar('\n');
    }
    return 0;
}