import java.util.*;
import java.io.*;

public class Main
{
	public static void main(String[] args)
	{
		FastScanner sc = new FastScanner();
		int n = sc.nextInt();
		int m = sc.nextInt();
		int l = sc.nextInt();
		long DIST_INF = 1111111111;
		int CHARGE_INF = 9999;

		long[][] c = new long[301][301];

		for(int i = 0 ; i < 301 ; i++){
			for(int j = 0 ; j < 301 ; j++){
				c[i][j] = DIST_INF;
			}
			c[i][i] = 0;
		}

		for(int i = 0 ; i < m ; i++){
			int x = sc.nextInt();
			int y = sc.nextInt();
			c[x][y] = sc.nextLong();
			c[y][x] = c[x][y];
		}

		//compute the distance between towns
		for(int k = 1 ; k <= n ; k++){
			for(int j = 1 ; j <= n ; j++){
				for(int i = 1 ; i <= n ; i++){
					if(c[i][j] > c[i][k] + c[k][j]){
						c[i][j] = c[i][k] + c[k][j];
					}
				}
			}
		}

		int[][] nTG = new int[301][301];
		for(int i = 1 ; i <= n ; i++){
			for(int j = 1 ; j <= n ; j++){
				if(c[i][j] <= l){
					nTG[i][j] = 1;
				}else{
					nTG[i][j] = CHARGE_INF;
				}
			}
		}

		for(int k = 1 ; k <= n ; k++){
			for(int j = 1 ; j <= n ; j++){
				for(int i = 1 ; i <= n ; i++){
					if(nTG[i][j] > nTG[i][k] + nTG[k][j]){
						nTG[i][j] = nTG[i][k] + nTG[k][j];
					}
				}
			}
		}

		int q = sc.nextInt();
		for(int i = 0 ; i < q ; i++){
			int s = sc.nextInt();
			int t = sc.nextInt();
			if(nTG[s][t] < CHARGE_INF){
				System.out.println(nTG[s][t]-1);
			}else{
				System.out.println(-1);
			}
		}
	}
}

class FastScanner {
    private final InputStream in = System.in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;
    private boolean hasNextByte() {
        if (ptr < buflen) {
            return true;
        }else{
            ptr = 0;
            try {
                buflen = in.read(buffer);
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (buflen <= 0) {
                return false;
            }
        }
        return true;
    }
    private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
    private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
    public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
    public String next() {
        if (!hasNext()) throw new NoSuchElementException();
        StringBuilder sb = new StringBuilder();
        int b = readByte();
        while(isPrintableChar(b)) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    public long nextLong() {
        if (!hasNext()) throw new NoSuchElementException();
        long n = 0;
        boolean minus = false;
        int b = readByte();
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        if (b < '0' || '9' < b) {
            throw new NumberFormatException();
        }
        while(true){
            if ('0' <= b && b <= '9') {
                n *= 10;
                n += b - '0';
            }else if(b == -1 || !isPrintableChar(b)){
                return minus ? -n : n;
            }else{
                throw new NumberFormatException();
            }
            b = readByte();
        }
    }
    public int nextInt() {
        long nl = nextLong();
        if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
        return (int) nl;
    }
    public double nextDouble() { return Double.parseDouble(next());}
}

Measured memory_bytes: 40340