For problem statement at 1000-1999/1100-1199/1140-1149/1140/problemF.txt this is a correct solution, but verifier at 1000-1999/1100-1199/1140-1149/1140/verifierF.go ends with case 2 mismatch
expected: 1 2 3
got: 1
2
3
input:
3
1 2
2 2
4 5
exit status 1 can you fix the verifier? package main

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

type Edge struct{ u, v int }

type History struct {
	u, v int
	ans  int64
}

var (
	tree    [][]Edge
	parent  []int
	sz      []int
	L, R    []int64
	ans     int64
	history []History
	res     []int64
)

func find(i int) int {
	for parent[i] != i {
		i = parent[i]
	}
	return i
}

func union(u, v int) {
	rootU := find(u)
	rootV := find(v)
	if rootU == rootV {
		history = append(history, History{-1, -1, 0})
		return
	}
	if sz[rootU] > sz[rootV] {
		rootU, rootV = rootV, rootU
	}
	history = append(history, History{rootU, rootV, ans})

	ans -= L[rootU]*R[rootU] + L[rootV]*R[rootV]
	parent[rootU] = rootV
	sz[rootV] += sz[rootU]
	L[rootV] += L[rootU]
	R[rootV] += R[rootU]
	ans += L[rootV]*R[rootV]
}

func rollback(target int) {
	for len(history) > target {
		last := history[len(history)-1]
		history = history[:len(history)-1]
		u, v := last.u, last.v
		if u != -1 {
			L[v] -= L[u]
			R[v] -= R[u]
			sz[v] -= sz[u]
			parent[u] = u
			ans = last.ans
		}
	}
}

func add(node, tl, tr, l, r, u, v int) {
	if l > r {
		return
	}
	if l == tl && r == tr {
		tree[node] = append(tree[node], Edge{u, v})
		return
	}
	tm := (tl + tr) / 2
	add(2*node, tl, tm, l, min(r, tm), u, v)
	add(2*node+1, tm+1, tr, max(l, tm+1), r, u, v)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func dfs(node, tl, tr int) {
	historySize := len(history)
	for _, e := range tree[node] {
		union(e.u, e.v)
	}
	if tl == tr {
		res[tl] = ans
	} else {
		tm := (tl + tr) / 2
		dfs(2*node, tl, tm)
		dfs(2*node+1, tm+1, tr)
	}
	rollback(historySize)
}

func main() {
	buffer, _ := io.ReadAll(os.Stdin)
	cursor := 0

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

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

	parent = make([]int, 600005)
	sz = make([]int, 600005)
	L = make([]int64, 600005)
	R = make([]int64, 600005)

	for i := 1; i <= 300000; i++ {
		parent[i] = i
		sz[i] = 1
		L[i] = 1
	}
	for i := 300001; i <= 600000; i++ {
		parent[i] = i
		sz[i] = 1
		R[i] = 1
	}

	tree = make([][]Edge, 4*q+1)
	res = make([]int64, q+1)
	active := make(map[int64]int)

	for i := 1; i <= q; i++ {
		x := nextInt()
		y := nextInt()
		key := (int64(x) << 32) | int64(y)

		if start, ok := active[key]; ok {
			add(1, 1, q, start, i-1, x, y+300000)
			delete(active, key)
		} else {
			active[key] = i
		}
	}

	for key, start := range active {
		x := int(key >> 32)
		y := int(key & 0xFFFFFFFF)
		add(1, 1, q, start, q, x, y+300000)
	}

	dfs(1, 1, q)

	out := bufio.NewWriter(os.Stdout)
	for i := 1; i <= q; i++ {
		out.WriteString(strconv.FormatInt(res[i], 10))
		out.WriteByte('\n')
	}
	out.Flush()
}