#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using Edge = pair<int, int>;
using Graph = vector<vector<Edge>>;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define SORT(v) sort((v).begin(), (v).end())
#define RSORT(v) sort((v).rbegin(), (v).rend())
const ll MOD = 1000000007;
const ll nmax = 301;
const ll INF = 1e10;
bool graph[nmax][nmax];

vector<vector<ll>> warshall_floyd(ll n, vector<vector<ll>> dist)
{
    for (size_t i = 0; i < n; i++)
    {
        for (size_t j = 0; j < n; j++)
        {
            for (size_t k = 0; k < n; k++)
            {
                dist[j][k] = min(dist[j][k], dist[j][i] + dist[i][k]);
            }
        }
    }

    return dist;
}

class UnionFind
{
public:
    vector<ll> Parent;

    UnionFind(ll N)
    {
        Parent = vector<ll>(N, -1);
    }
    ll find(ll A)
    {
        if (Parent[A] < 0)
            return A;
        return Parent[A] = find(Parent[A]);
    }

    ll size(ll A)
    {
        return -Parent[find(A)];
    }

    bool Union(ll A, ll B)
    {
        A = find(A);
        B = find(B);
        if (A == B)
        {
            return false;
        }
        if (size(A) < size(B))
            swap(A, B);

        Parent[A] += Parent[B];
        Parent[B] = A;

        return true;
    }
};

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

ll lcm(ll a, ll b)
{
    ll g = gcd(a, b);
    return a / g * b;
}

ll mulMod(ll a, ll b)
{
    return (((a % MOD) * (b % MOD)) % MOD);
}

ll powMod(ll a, ll p)
{
    if (p == 0)
    {
        return 1;
    }
    else if (p % 2 == 0)
    {
        ll half = powMod(a, p / 2);
        return mulMod(half, half);
    }
    else
    {
        return mulMod(powMod(a, p - 1), a);
    }
}

ll ceil(ll a, ll b)
{
    return (a + b - 1) / b;
}

void solve(long long N, long long M, long long L, std::vector<long long> A, std::vector<long long> B, std::vector<long long> C, long long Q, std::vector<long long> s, std::vector<long long> t)
{
    vector<vector<ll>> dist = vector<vector<ll>>(nmax, vector<ll>(nmax, INF));
    vector<vector<ll>> dist2 = vector<vector<ll>>(nmax, vector<ll>(nmax, INF));
    for (ll i = 0; i < M; i++)
    {
        dist[A[i] - 1][B[i] - 1] = C[i];
        dist[B[i] - 1][A[i] - 1] = C[i];
    }

    for (int i = 0; i < N; i++)
    {
        dist[i][i] = 0;
    }

    dist = warshall_floyd(N, dist);

    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if (dist[i][j] <= L)
            {
                dist2[i][j] = 1;
            }
        }
    }

    for (int i = 0; i < N; i++)
    {
        dist2[i][i] = 0;
    }
    dist2 = warshall_floyd(N, dist2);

    for (int i = 0; i < Q; i++)
    {
        if (dist2[s[i] - 1][t[i] - 1] == INF)
        {
            cout << -1 << endl;
        }
        else
        {
            cout << dist2[s[i] - 1][t[i] - 1] - 1 << endl;
        }
    }
}

int main()
{
    long long N;
    scanf("%lld", &N);
    long long M;
    scanf("%lld", &M);
    long long L;
    scanf("%lld", &L);
    std::vector<long long> A(M);
    std::vector<long long> B(M);
    std::vector<long long> C(M);
    for (int i = 0; i < M; i++)
    {
        scanf("%lld", &A[i]);
        scanf("%lld", &B[i]);
        scanf("%lld", &C[i]);
    }
    long long Q;
    scanf("%lld", &Q);
    std::vector<long long> s(Q);
    std::vector<long long> t(Q);
    for (int i = 0; i < Q; i++)
    {
        scanf("%lld", &s[i]);
        scanf("%lld", &t[i]);
    }
    solve(N, M, L, std::move(A), std::move(B), std::move(C), Q, std::move(s), std::move(t));
    return 0;
}


Measured memory_bytes: 4992