package main

import (
	"io"
	"os"
	"strconv"
)

const MOD int64 = 998244353
const MAXN = 500000

type FastScanner struct {
	data []byte
	idx  int
	n    int
}

func NewFastScanner() *FastScanner {
	data, _ := io.ReadAll(os.Stdin)
	return &FastScanner{data: data, n: len(data)}
}

func (fs *FastScanner) NextInt() int {
	for fs.idx < fs.n {
		c := fs.data[fs.idx]
		if c == '-' || (c >= '0' && c <= '9') {
			break
		}
		fs.idx++
	}
	sign := 1
	if fs.data[fs.idx] == '-' {
		sign = -1
		fs.idx++
	}
	val := 0
	for fs.idx < fs.n {
		c := fs.data[fs.idx]
		if c < '0' || c > '9' {
			break
		}
		val = val*10 + int(c-'0')
		fs.idx++
	}
	return sign * val
}

var inv [MAXN + 1]int64

func comb(d int64, l int) int64 {
	if d < 0 {
		return 0
	}
	res := int64(1)
	for i := 1; i <= l; i++ {
		res = res * ((d + int64(i)) % MOD) % MOD
		res = res * inv[i] % MOD
	}
	return res
}

func main() {
	inv[1] = 1
	for i := 2; i <= MAXN; i++ {
		inv[i] = MOD - (MOD/int64(i))*inv[int(MOD%int64(i))]%MOD
	}

	fs := NewFastScanner()
	t := fs.NextInt()

	out := make([]byte, 0, t*12)

	var L, R []int
	var V []int64
	var stack []int

	for ; t > 0; t-- {
		n := fs.NextInt()
		C := int64(fs.NextInt())

		if cap(L) < n+1 {
			L = make([]int, n+1)
			R = make([]int, n+1)
			V = make([]int64, n+1)
		} else {
			L = L[:n+1]
			R = R[:n+1]
			V = V[:n+1]
		}

		for i := 1; i <= n; i++ {
			L[i] = fs.NextInt()
			R[i] = fs.NextInt()
			V[i] = int64(fs.NextInt())
		}

		if cap(stack) < n {
			stack = make([]int, 0, n)
		} else {
			stack = stack[:0]
		}

		ans := int64(1)
		prevPos := 0
		prevVal := int64(1)
		pos := 0
		cur := 1

		for cur != -1 || len(stack) > 0 {
			for cur != -1 {
				stack = append(stack, cur)
				cur = L[cur]
			}
			cur = stack[len(stack)-1]
			stack = stack[:len(stack)-1]

			pos++
			val := V[cur]
			if val != -1 {
				if val < prevVal {
					ans = 0
				} else if ans != 0 {
					ans = ans * comb(val-prevVal, pos-prevPos-1) % MOD
				}
				prevPos = pos
				prevVal = val
			}

			cur = R[cur]
		}

		if prevVal > C {
			ans = 0
		} else if ans != 0 {
			ans = ans * comb(C-prevVal, n-prevPos) % MOD
		}

		out = strconv.AppendInt(out, ans, 10)
		out = append(out, '\n')
	}

	os.Stdout.Write(out)
}