/*
URL:
https://atcoder.jp/contests/abc143/tasks/abc143_e
*/

package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

/*******************************************************************/

var (
	n, m, l int
	q       int

	A [300 + 5][300 + 5]int
	// G [300 + 5][]Edge
	G [][]int
)

func main() {
	n, m, l = ReadInt3()
	for i := 0; i < n; i++ {
		row := make([]int, n)
		for j := 0; j < n; j++ {
			row[j] = INF_BIT30
		}
		G = append(G, row)
	}
	for i := 0; i < m; i++ {
		a, b, c := ReadInt3()
		a--
		b--

		// G[a] = append(G[a], Edge{to: b, cost: c})
		// G[b] = append(G[b], Edge{to: a, cost: c})
		G[a][b] = c
		G[b][a] = c
	}

	vinf := V{gas: -1, times: INF_BIT60} // inf
	einf := INF_BIT30
	vzero := V{gas: l, times: 0} // zerp
	less := func(l, r V) bool {
		if l.times < r.times {
			return true
		} else if l.times > r.times {
			return false
		} else {
			return l.gas > r.gas
		}
	}
	// genNextV := func(cv *Vertex, e Edge) V {
	genNextV := func(cv V, e int) V {
		// if l < e.cost {
		if l < e {
			return vinf
		}

		if cv.gas >= e {
			return V{gas: cv.gas - e, times: cv.times}
		}

		return V{gas: l - e, times: cv.times + 1}
	}
	// ds := NewDijkstraSolve(vinf, vzero, less, genNextV)
	ds := NewDijkstraSolver(vinf, einf, less, genNextV)

	for i := 0; i < n; i++ {
		// dp := ds.Dijkstra([]int{i}, n, G[:n])
		// dp := ds.Dijkstra([]StartPoint{StartPoint{id: i, vinit: vzero}}, n, G[:n])
		dp := ds.Dijkstra([]StartPoint{StartPoint{id: i, vinit: vzero}}, n, G)

		for j := 0; j < n; j++ {
			if i == j {
				continue
			}

			A[i][j] = dp[j].times
		}
	}

	q = ReadInt()
	for i := 0; i < q; i++ {
		s, t := ReadInt2()
		s--
		t--

		if A[s][t] >= INF_BIT60 {
			fmt.Println(-1)
		} else {
			fmt.Println(A[s][t])
		}
	}
}

// DP value type
type V struct {
	gas, times int
}

type StartPoint struct {
	id    int
	vinit V
}

type DijkstraSolver struct {
	vinf V
	einf int
	Less func(l, r V) bool // Less returns whether l is strictly less than r, and is also used for priority queue.
	// GenNextV func(cv *Vertex, e Edge) V // GenNextV returns next value considered by transition.
	GenNextV func(cv V, e int) V // GenNextV returns next value considered by transition.
}

func NewDijkstraSolver(
	vinf V, einf int, Less func(l, r V) bool, GenNextV func(cv V, e int) V,
) *DijkstraSolver {
	ds := new(DijkstraSolver)

	// __less = Less

	ds.vinf, ds.Less, ds.GenNextV = vinf, Less, GenNextV
	ds.einf = einf

	return ds
}

// InitAll returns initialized dp and colors slices.
func (ds *DijkstraSolver) InitAll(n int) (dp []V, colors []int) {
	dp, colors = make([]V, n), make([]int, n)
	for i := 0; i < n; i++ {
		dp[i] = ds.vinf
		colors[i] = WHITE
	}

	return dp, colors
}

// InitStartPoint returns initialized priority queue, and update dp and colors slices.
// *This function update arguments (side effects).*
// func (ds *DijkstraSolver) InitStartPoint(S []StartPoint, dp []V, colors []int) *VertexPQ {
func (ds *DijkstraSolver) InitStartPoint(S []StartPoint, dp []V, colors []int) {
	// pq := NewVertexPQ()

	for _, sp := range S {
		// pq.push(&Vertex{id: sp.id, v: sp.vinit})
		dp[sp.id] = sp.vinit
		colors[sp.id] = GRAY
	}

	// return pq
}

// verified by [ABC143-E](https://atcoder.jp/contests/abc143/tasks/abc143_e)
// func (ds *DijkstraSolver) Dijkstra(S []StartPoint, n int, AG [][]Edge) []V {
func (ds *DijkstraSolver) Dijkstra(S []StartPoint, n int, AG [][]int) []V {
	// initialize data
	dp, colors := ds.InitAll(n)

	// configure about start points (some problems have multi start points)
	// pq := ds.InitStartPoint(S, dp, colors)
	ds.InitStartPoint(S, dp, colors)

	// body of dijkstra algorithm
	// for pq.Len() > 0 {
	// 	pop := pq.pop()
	// 	colors[pop.id] = BLACK
	// 	if ds.Less(dp[pop.id], pop.v) {
	// 		continue
	// 	}

	// 	// to next node
	// 	for _, e := range AG[pop.id] {
	// 		if colors[e.to] == BLACK {
	// 			continue
	// 		}

	// 		// update optimal value of the next node
	// 		nv := ds.GenNextV(pop, e)

	// 		if ds.Less(nv, dp[e.to]) {
	// 			dp[e.to] = nv
	// 			pq.push(&Vertex{id: e.to, v: nv})
	// 			colors[e.to] = GRAY
	// 		}
	// 	}
	// }

	for {
		minv := ds.vinf
		u := -1
		for i := 0; i < n; i++ {
			if ds.Less(dp[i], minv) && colors[i] != BLACK {
				u = i
				minv = dp[i]
			}
		}
		if u == -1 {
			break
		}

		colors[u] = BLACK

		for v := 0; v < n; v++ {
			if colors[v] != BLACK && AG[u][v] != ds.einf {
				nv := ds.GenNextV(dp[u], AG[u][v])
				if ds.Less(nv, dp[v]) {
					dp[v] = nv
					colors[v] = GRAY
				}
			}
		}
	}

	return dp
}

// const (
// 	MAX   = 2500 + 5
// 	INFTY = 1 << 30
// )

// var n int           // ノード数
// var M [MAX][MAX]int // グラフ（隣接行列形式）

// // O(|V|^2)
// // 各ノードの最短路の長さを返す
// func dijkstra(sid int) []int {
// 	var minv int
// 	d, color := make([]int, MAX), make([]int, MAX)

// 	for i := 0; i < n; i++ {
// 		d[i] = INFTY
// 		color[i] = WHITE
// 	}

// 	d[sid] = 0
// 	color[sid] = GRAY
// 	for {
// 		minv = INFTY
// 		u := -1
// 		for i := 0; i < n; i++ {
// 			if minv > d[i] && color[i] != BLACK {
// 				u = i
// 				minv = d[i]
// 			}
// 		}
// 		if u == -1 {
// 			break
// 		}

// 		color[u] = BLACK

// 		for v := 0; v < n; v++ {
// 			if color[v] != BLACK && M[u][v] != INFTY {
// 				if d[v] > d[u]+M[u][v] {
// 					d[v] = d[u] + M[u][v]
// 					color[v] = GRAY
// 				}
// 			}
// 		}
// 	}

// 	return d
// }

const (
	// General purpose
	MOD = 1000000000 + 7
	// MOD          = 998244353
	ALPHABET_NUM = 26
	INF_INT64    = math.MaxInt64
	INF_BIT60    = 1 << 60
	INF_INT32    = math.MaxInt32
	INF_BIT30    = 1 << 30
	NIL          = -1

	// for dijkstra, prim, and so on
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

/*******************************************************************/

/********** bufio setting **********/

func init() {
	// bufio.ScanWords <---> bufio.ScanLines
	ReadString = newReadString(os.Stdin, bufio.ScanWords)
	stdout = bufio.NewWriter(os.Stdout)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*********** Input ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func newReadString(ior io.Reader, sf bufio.SplitFunc) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	r.Split(sf)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// ReadInt returns an integer.
func ReadInt() int {
	return int(readInt64())
}
func ReadInt2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func ReadInt3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func ReadInt4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// ReadInt64 returns as integer as int64.
func ReadInt64() int64 {
	return readInt64()
}
func ReadInt64_2() (int64, int64) {
	return readInt64(), readInt64()
}
func ReadInt64_3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func ReadInt64_4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// ReadIntSlice returns an integer slice that has n integers.
func ReadIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt()
	}
	return b
}

// ReadInt64Slice returns as int64 slice that has n integers.
func ReadInt64Slice(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadInt64()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Output ***********/

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintIntsLine returns integers string delimited by a space.
func PrintInts64Line(A ...int64) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.FormatInt(A[i], 10) // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintfBufStdout is function for output strings to buffered os.Stdout.
// You may have to call stdout.Flush() finally.
func PrintfBufStdout(format string, a ...interface{}) {
	fmt.Fprintf(stdout, format, a...)
}

/*********** Debugging ***********/

// PrintfDebug is wrapper of fmt.Fprintf(os.Stderr, format, a...)
func PrintfDebug(format string, a ...interface{}) {
	fmt.Fprintf(os.Stderr, format, a...)
}

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}


Measured memory_bytes: 6912