import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.io.BufferedWriter;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

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

    static class ETravelByCar {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.readInt();
            int m = in.readInt();
            int l = in.readInt();
            int[] a = new int[m];
            int[] b = new int[m];
            int[] c = new int[m];
            in.readIntArrays(a, b, c);
            int q = in.readInt();
            int[] s = new int[q];
            int[] t = new int[q];
            in.readIntArrays(s, t);
            MiscUtils.decreaseByOne(a, b, s, t);

            long[][] d = new long[n][n];
            long INF = (long) 1e18;
            ArrayUtils.fill(d, INF);
            for (int i = 0; i < n; i++) d[i][i] = 0;
            for (int i = 0; i < m; i++) d[a[i]][b[i]] = d[b[i]][a[i]] = c[i];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    for (int k = 0; k < n; k++) {
                        d[j][k] = Math.min(d[j][k], d[j][i] + d[i][k]);
                    }
                }
            }

            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    if (i == j) continue;
                    d[i][j] = d[i][j] <= l ? 1 : INF;
                }
            }
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < n; j++) {
                    for (int k = 0; k < n; k++) {
                        d[j][k] = Math.min(d[j][k], d[j][i] + d[i][k]);
                    }
                }
            }

            for (int i = 0; i < q; i++) {
                out.printLine(d[s[i]][t[i]] == INF ? -1 : d[s[i]][t[i]] - 1);
            }
        }

    }

    static class ArrayUtils {
        public static void fill(long[][] array, long value) {
            for (long[] row : array) {
                Arrays.fill(row, value);
            }
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public void readIntArrays(int[]... arrays) {
            for (int i = 0; i < arrays[0].length; i++) {
                for (int j = 0; j < arrays.length; j++) {
                    arrays[j][i] = readInt();
                }
            }
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int readInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void printLine(long i) {
            writer.println(i);
        }

    }

    static class MiscUtils {
        public static void decreaseByOne(int[]... arrays) {
            for (int[] array : arrays) {
                for (int i = 0; i < array.length; i++) {
                    array[i]--;
                }
            }
        }

    }
}



Measured memory_bytes: 31808