For problem statement at 1000-1999/1400-1499/1410-1419/1418/problemG.txt this is a correct solution, but verifier at 1000-1999/1400-1499/1410-1419/1418/verifierG.go ends with case 2: runtime error: exit status 2
panic: runtime error: index out of range [3] with length 3

goroutine 1 [running]:
main.main()
	/tmp/build-2253525526/solution.go:51 +0x5e0

input:
2
3 1
exit status 1 can you fix the verifier? package main

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

type Key struct {
	a uint64
	b uint64
}

func mix(x uint64) uint64 {
	x += 0x9e3779b97f4a7c15
	x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9
	x = (x ^ (x >> 27)) * 0x94d049bb133111eb
	return x ^ (x >> 31)
}

func nextInt(data []byte, idx *int) int {
	n := len(data)
	for *idx < n && (data[*idx] < '0' || data[*idx] > '9') {
		*idx = *idx + 1
	}
	v := 0
	for *idx < n && data[*idx] >= '0' && data[*idx] <= '9' {
		v = v*10 + int(data[*idx]-'0')
		*idx = *idx + 1
	}
	return v
}

func main() {
	data, _ := io.ReadAll(os.Stdin)
	pos := 0
	n := nextInt(data, &pos)

	a := make([]int, n+1)
	p := make([]Key, n+1)
	mod := make([]byte, n+1)

	var h1, h2 uint64
	const seed2 uint64 = 0x517cc1b727220a95

	for i := 1; i <= n; i++ {
		x := nextInt(data, &pos)
		a[i] = x
		r1 := mix(uint64(x))
		r2 := mix(uint64(x) + seed2)
		switch mod[x] {
		case 0:
			h1 += r1
			h2 += r2
			mod[x] = 1
		case 1:
			h1 += r1
			h2 += r2
			mod[x] = 2
		default:
			h1 -= r1 + r1
			h2 -= r2 + r2
			mod[x] = 0
		}
		p[i] = Key{h1, h2}
	}

	cnt := make([]int, n+1)
	active := make(map[Key]int, n+1)

	l := 1
	var ans int64

	for r := 1; r <= n; r++ {
		active[p[r-1]]++
		x := a[r]
		cnt[x]++
		for cnt[x] > 3 {
			active[p[l-1]]--
			cnt[a[l]]--
			l++
		}
		ans += int64(active[p[r]])
	}

	os.Stdout.Write([]byte(strconv.FormatInt(ans, 10)))
}