import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.IOException;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author anand.oza
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        ETravelByCar solver = new ETravelByCar();
        solver.solve(1, in, out);
        out.close();
    }

    static class ETravelByCar {
        private static final long INF = Long.MAX_VALUE / 3;

        public void solve(int testNumber, InputReader in, PrintWriter out) {
            int n = in.nextInt();
            int m = in.nextInt();
            long l = in.nextLong();

            long[][] adj = new long[n][n];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    adj[i][j] = i == j ? 0 : INF;
                }
            }
            for (int i = 0; i < m; i++) {
                int a = in.nextInt() - 1;
                int b = in.nextInt() - 1;
                long c = in.nextLong();

                adj[a][b] = adj[b][a] = c;
            }

            for (int k = 0; k < n; k++) {
                for (int i = 0; i < n; i++) {
                    for (int j = 0; j < n; j++) {
                        adj[i][j] = Math.min(adj[i][j], adj[i][k] + adj[k][j]);
                    }
                }
            }

            long[][] oldAdj = adj.clone();

            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    adj[i][j] = oldAdj[i][j] <= l ? 1 : INF;
                    if (i == j) {
                        adj[i][j] = 0;
                    }
                }
            }


            for (int k = 0; k < n; k++) {
                for (int i = 0; i < n; i++) {
                    for (int j = 0; j < n; j++) {
                        adj[i][j] = Math.min(adj[i][j], adj[i][k] + adj[k][j]);
                    }
                }
            }

            int q = in.nextInt();
            for (int query = 0; query < q; query++) {
                int s = in.nextInt() - 1;
                int t = in.nextInt() - 1;

                long answer = adj[s][t];
                if (answer >= INF) {
                    answer = -1;
                } else {
                    answer--; // first fill free
                }
                out.println(answer);
            }
        }

    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

    }
}


Measured memory_bytes: 45232