For problem statement at 0-999/800-899/810-819/813/problemF.txt this is a correct solution, but verifier at 0-999/800-899/810-819/813/verifierF.go ends with All tests passed can you fix the verifier? ```go
package main

import (
	"fmt"
	"sort"
)

type Pair struct {
	x, y int
}

type Change struct {
	kind   string
	node   int
	oldval int
}

var (
	n, q        int
	segtree     [][]Pair
	parent      []int
	rank        []int
	bipar       []int
	count_bad   []int
	total_bad   int
	stackc      []Change
	active      map[[2]int]struct{}
	ans         []string
)

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 update(node, s, e, ql, qr int, edge Pair) {
	if ql > e || qr < s {
		return
	}
	if ql <= s && e <= qr {
		segtree[node] = append(segtree[node], edge)
		return
	}
	mid := (s + e) / 2
	update(2*node, s, mid, ql, qr, edge)
	update(2*node+1, mid+1, e, ql, qr, edge)
}

func find(u int) (int, int) {
	p := u
	par := 0
	for p != parent[p] {
		par ^= bipar[p]
		p = parent[p]
	}
	return p, par
}

func bool2int(b bool) int {
	if b {
		return 1
	}
	return 0
}

func add_edge(u, v int) {
	pu, paru := find(u)
	pv, parv := find(v)
	diff := paru ^ parv
	if pu == pv {
		if diff == 0 {
			old_count := count_bad[pu]
			new_count := old_count + 1
			if old_count == 0 {
				stackc = append(stackc, Change{"total_bad", 0, total_bad})
				total_bad++
			}
			stackc = append(stackc, Change{"count", pu, old_count})
			count_bad[pu] = new_count
		}
		return
	}
	// union
	if rank[pu] > rank[pv] {
		pu, pv = pv, pu
		paru, parv = parv, paru
	}
	old_parent := parent[pu]
	old_bipar := bipar[pu]
	old_rank := rank[pv]
	old_count := count_bad[pv]
	new_count := count_bad[pu] + count_bad[pv]
	old_num := bool2int(count_bad[pu] > 0) + bool2int(old_count > 0)
	new_num := bool2int(new_count > 0)
	if old_num != new_num {
		stackc = append(stackc, Change{"total_bad", 0, total_bad})
		total_bad += new_num - old_num
	}
	stackc = append(stackc, Change{"parent", pu, old_parent})
	stackc = append(stackc, Change{"bipar", pu, old_bipar})
	stackc = append(stackc, Change{"rank", pv, old_rank})
	stackc = append(stackc, Change{"count", pv, old_count})
	parent[pu] = pv
	bipar[pu] = paru ^ parv ^ 1
	if rank[pu] == rank[pv] {
		rank[pv]++
	}
	count_bad[pv] = new_count
}

func dfs(node, start, end int) {
	old_stack_size := len(stackc)
	var newly_processed [][2]int
	for _, e := range segtree[node] {
		pair := [2]int{min(e.x, e.y), max(e.x, e.y)}
		if _, ok := active[pair]; !ok {
			add_edge(e.x, e.y)
			active[pair] = struct{}{}
			newly_processed = append(newly_processed, pair)
		}
	}
	if start == end {
		if total_bad > 0 {
			ans[start] = "NO"
		} else {
			ans[start] = "YES"
		}
	} else {
		mid := (start + end) / 2
		dfs(2*node, start, mid)
		dfs(2*node+1, mid+1, end)
	}
	// rollback DSU changes
	for len(stackc) > old_stack_size {
		ch := stackc[len(stackc)-1]
		stackc = stackc[:len(stackc)-1]
		switch ch.kind {
		case "parent":
			parent[ch.node] = ch.oldval
		case "bipar":
			bipar[ch.node] = ch.oldval
		case "rank":
			rank[ch.node] = ch.oldval
		case "count":
			count_bad[ch.node] = ch.oldval
		case "total_bad":
			total_bad = ch.oldval
		}
	}
	// remove from active
	for _, pair := range newly_processed {
		delete(active, pair)
	}
}

func main() {
	fmt.Scan(&n, &q)
	segtree = make([][]Pair, 4*q+4)
	toggles := make(map[[2]int][]int)
	for i := 1; i <= q; i++ {
		var x, y int
		fmt.Scan(&x, &y)
		if x > y {
			x, y = y, x
		}
		pair := [2]int{x, y}
		toggles[pair] = append(toggles[pair], i)
	}
	for key, val := range toggles {
		t := val
		sort.Ints(t)
		for j := 0; j < len(t); j += 2 {
			l := t[j]
			r := q
			if j+1 < len(t) {
				r = t[j+1] - 1
			}
			if l <= r {
				update(1, 1, q, l, r, Pair{key[0], key[1]})
			}
		}
	}
	parent = make([]int, n+1)
	rank = make([]int, n+1)
	bipar = make([]int, n+1)
	count_bad = make([]int, n+1)
	for i := 1; i <= n; i++ {
		parent[i] = i
	}
	total_bad = 0
	active = make(map[[2]int]struct{})
	ans = make([]string, q+1)
	dfs(1, 1, q)
	for i := 1; i <= q; i++ {
		fmt.Println(ans[i])
	}
}
```