For problem statement at 1000-1999/1600-1699/1610-1619/1613/problemF.txt this is a correct solution, but verifier at 1000-1999/1600-1699/1610-1619/1613/verifierF.go ends with All tests passed can you fix the verifier? package main

import (
	"container/heap"
	"fmt"
	"io"
	"os"
)

const MOD = 998244353
const G = 3

func power(base, exp int64) int64 {
	res := int64(1)
	base %= MOD
	for exp > 0 {
		if exp%2 == 1 {
			res = (res * base) % MOD
		}
		base = (base * base) % MOD
		exp /= 2
	}
	return res
}

func modInverse(n int64) int64 {
	return power(n, MOD-2)
}

func ntt(a []int64, invert bool) {
	n := len(a)
	j := 0
	for i := 1; i < n; i++ {
		bit := n >> 1
		for j&bit != 0 {
			j ^= bit
			bit >>= 1
		}
		j ^= bit
		if i < j {
			a[i], a[j] = a[j], a[i]
		}
	}

	for length := 2; length <= n; length <<= 1 {
		half := length >> 1
		wLen := power(G, (MOD-1)/int64(length))
		if invert {
			wLen = modInverse(wLen)
		}
		for i := 0; i < n; i += length {
			w := int64(1)
			for j := 0; j < half; j++ {
				u := a[i+j]
				v := (a[i+j+half] * w) % MOD
				a[i+j] = u + v
				if a[i+j] >= MOD {
					a[i+j] -= MOD
				}
				a[i+j+half] = u - v + MOD
				if a[i+j+half] >= MOD {
					a[i+j+half] -= MOD
				}
				w = (w * wLen) % MOD
			}
		}
	}

	if invert {
		invN := modInverse(int64(n))
		for i := 0; i < n; i++ {
			a[i] = (a[i] * invN) % MOD
		}
	}
}

func multiply(a, b []int64) []int64 {
	n1 := len(a)
	n2 := len(b)
	if n1 == 0 || n2 == 0 {
		return []int64{}
	}
	if n1 < 64 || n2 < 64 || n1*n2 <= 4096 {
		res := make([]uint64, n1+n2-1)
		for i := 0; i < n1; i++ {
			if a[i] == 0 {
				continue
			}
			ui := uint64(a[i])
			for j := 0; j < n2; j++ {
				res[i+j] += ui * uint64(b[j])
				if res[i+j] >= 8e18 {
					res[i+j] %= MOD
				}
			}
		}
		out := make([]int64, n1+n2-1)
		for i := 0; i < len(out); i++ {
			out[i] = int64(res[i] % MOD)
		}
		return out
	}

	n := 1
	for n < n1+n2-1 {
		n <<= 1
	}

	A := make([]int64, n)
	copy(A, a)
	B := make([]int64, n)
	copy(B, b)

	ntt(A, false)
	ntt(B, false)

	for i := 0; i < n; i++ {
		A[i] = (A[i] * B[i]) % MOD
	}

	ntt(A, true)

	return A[:n1+n2-1]
}

var fact, invFact []int64

func initFactorials(n int) {
	fact = make([]int64, n+1)
	invFact = make([]int64, n+1)
	fact[0] = 1
	invFact[0] = 1
	for i := 1; i <= n; i++ {
		fact[i] = (fact[i-1] * int64(i)) % MOD
	}
	invFact[n] = modInverse(fact[n])
	for i := n - 1; i >= 1; i-- {
		invFact[i] = (invFact[i+1] * int64(i+1)) % MOD
	}
}

func nCr(n, r int) int64 {
	if r < 0 || r > n {
		return 0
	}
	return fact[n] * invFact[r] % MOD * invFact[n-r] % MOD
}

func buildPoly(d int64, C int) []int64 {
	P := make([]int64, C+1)
	dPow := int64(1)
	for k := 0; k <= C; k++ {
		P[k] = (nCr(C, k) * dPow) % MOD
		dPow = (dPow * d) % MOD
	}
	return P
}

type Poly []int64

type PolyHeap []Poly

func (h PolyHeap) Len() int           { return len(h) }
func (h PolyHeap) Less(i, j int) bool { return len(h[i]) < len(h[j]) }
func (h PolyHeap) Swap(i, j int)      { h[i], h[j] = h[j], h[i] }

func (h *PolyHeap) Push(x interface{}) {
	*h = append(*h, x.(Poly))
}

func (h *PolyHeap) Pop() interface{} {
	old := *h
	n := len(old)
	x := old[n-1]
	*h = old[0 : n-1]
	return x
}

func main() {
	input, _ := io.ReadAll(os.Stdin)
	idx := 0

	nextInt := func() int {
		for idx < len(input) && (input[idx] < '0' || input[idx] > '9') {
			idx++
		}
		if idx >= len(input) {
			return 0
		}
		res := 0
		for idx < len(input) && input[idx] >= '0' && input[idx] <= '9' {
			res = res*10 + int(input[idx]-'0')
			idx++
		}
		return res
	}

	n := nextInt()
	if n == 0 {
		return
	}

	adj := make([][]int, n+1)
	for i := 0; i < n-1; i++ {
		u := nextInt()
		v := nextInt()
		adj[u] = append(adj[u], v)
		adj[v] = append(adj[v], u)
	}

	initFactorials(n + 5)

	deg := make([]int, n+1)
	queue := make([]int, 0, n)
	queue = append(queue, 1)
	visited := make([]bool, n+1)
	visited[1] = true

	for len(queue) > 0 {
		u := queue[0]
		queue = queue[1:]
		outCount := 0
		for _, v := range adj[u] {
			if !visited[v] {
				visited[v] = true
				outCount++
				queue = append(queue, v)
			}
		}
		deg[u] = outCount
	}

	counts := make(map[int]int)
	for i := 1; i <= n; i++ {
		if deg[i] > 0 {
			counts[deg[i]]++
		}
	}

	h := &PolyHeap{}
	heap.Init(h)

	for d, c := range counts {
		heap.Push(h, Poly(buildPoly(int64(d), c)))
	}

	if h.Len() == 0 {
		heap.Push(h, Poly{1})
	}

	for h.Len() > 1 {
		p1 := heap.Pop(h).(Poly)
		p2 := heap.Pop(h).(Poly)
		p3 := multiply(p1, p2)
		heap.Push(h, Poly(p3))
	}

	ansPoly := heap.Pop(h).(Poly)

	ans := int64(0)
	for k := 0; k < len(ansPoly); k++ {
		term := (ansPoly[k] * fact[n-k]) % MOD
		if k%2 == 1 {
			ans = (ans - term + MOD) % MOD
		} else {
			ans = (ans + term) % MOD
		}
	}

	fmt.Println(ans)
}