For problem statement at 1000-1999/1800-1899/1870-1879/1878/problemG.txt this is a correct solution, but verifier at 1000-1999/1800-1899/1870-1879/1878/verifierG.go ends with All 100 tests passed can you fix the verifier? package main

import (
	"bufio"
	"fmt"
	"math/bits"
	"os"
	"sort"
)

type SegTree struct {
	n    int
	tree []int
}

func NewSegTree(arr []int) *SegTree {
	n := len(arr)
	st := &SegTree{n: n, tree: make([]int, 4*n)}
	st.build(1, 0, n-1, arr)
	return st
}

func (st *SegTree) build(id, l, r int, arr []int) {
	if l == r {
		st.tree[id] = arr[l]
		return
	}
	m := (l + r) >> 1
	st.build(id<<1, l, m, arr)
	st.build(id<<1|1, m+1, r, arr)
	st.tree[id] = st.tree[id<<1] | st.tree[id<<1|1]
}

func (st *SegTree) QueryOr(l, r int) int {
	if l > r {
		return 0
	}
	return st.qOr(1, 0, st.n-1, l, r)
}

func (st *SegTree) qOr(id, l, r, ql, qr int) int {
	if ql <= l && r <= qr {
		return st.tree[id]
	}
	m := (l + r) >> 1
	res := 0
	if ql <= m {
		res |= st.qOr(id<<1, l, m, ql, qr)
	}
	if qr > m {
		res |= st.qOr(id<<1|1, m+1, r, ql, qr)
	}
	return res
}

func (st *SegTree) FindFirstLeft(l, r int, bit int) int {
	return st.ffl(1, 0, st.n-1, l, r, bit)
}

func (st *SegTree) ffl(id, l, r, ql, qr, bit int) int {
	if r < ql || l > qr {
		return -1
	}
	if ((st.tree[id] >> bit) & 1) == 0 {
		return -1
	}
	if l == r {
		return l
	}
	m := (l + r) >> 1
	res := st.ffl(id<<1, l, m, ql, qr, bit)
	if res != -1 {
		return res
	}
	return st.ffl(id<<1|1, m+1, r, ql, qr, bit)
}

func (st *SegTree) FindFirstRight(l, r int, bit int) int {
	return st.ffr(1, 0, st.n-1, l, r, bit)
}

func (st *SegTree) ffr(id, l, r, ql, qr, bit int) int {
	if r < ql || l > qr {
		return -1
	}
	if ((st.tree[id] >> bit) & 1) == 0 {
		return -1
	}
	if l == r {
		return l
	}
	m := (l + r) >> 1
	res := st.ffr(id<<1|1, m+1, r, ql, qr, bit)
	if res != -1 {
		return res
	}
	return st.ffr(id<<1, l, m, ql, qr, bit)
}

type FastScanner struct {
	r *bufio.Reader
}

func NewFastScanner() *FastScanner {
	return &FastScanner{r: bufio.NewReaderSize(os.Stdin, 1<<20)}
}

func (fs *FastScanner) NextInt() int {
	sign := 1
	val := 0
	c, _ := fs.r.ReadByte()
	for (c < '0' || c > '9') && c != '-' {
		c, _ = fs.r.ReadByte()
	}
	if c == '-' {
		sign = -1
		c, _ = fs.r.ReadByte()
	}
	for c >= '0' && c <= '9' {
		val = val*10 + int(c-'0')
		c, _ = fs.r.ReadByte()
	}
	return sign * val
}

func main() {
	in := NewFastScanner()
	out := bufio.NewWriterSize(os.Stdout, 1<<20)
	defer out.Flush()

	t := in.NextInt()
	for ; t > 0; t-- {
		n := in.NextInt()
		a := make([]int, n)
		for i := 0; i < n; i++ {
			a[i] = in.NextInt()
		}
		adj := make([][]int, n)
		for i := 0; i < n-1; i++ {
			u := in.NextInt() - 1
			v := in.NextInt() - 1
			adj[u] = append(adj[u], v)
			adj[v] = append(adj[v], u)
		}
		parent := make([]int, n)
		depth := make([]int, n)
		for i := 0; i < n; i++ {
			parent[i] = -1
		}
		order := make([]int, 0, n)
		stack := make([]int, 0, n)
		stack = append(stack, 0)
		parent[0] = 0
		depth[0] = 0
		for len(stack) > 0 {
			u := stack[len(stack)-1]
			stack = stack[:len(stack)-1]
			order = append(order, u)
			for _, v := range adj[u] {
				if v == parent[u] {
					continue
				}
				parent[v] = u
				depth[v] = depth[u] + 1
				stack = append(stack, v)
			}
		}
		size := make([]int, n)
		heavy := make([]int, n)
		for i := 0; i < n; i++ {
			heavy[i] = -1
		}
		for i := n - 1; i >= 0; i-- {
			u := order[i]
			size[u] = 1
			maxsz := 0
			for _, v := range adj[u] {
				if v == parent[u] {
					continue
				}
				size[u] += size[v]
				if size[v] > maxsz {
					maxsz = size[v]
					heavy[u] = v
				}
			}
		}
		head := make([]int, n)
		pos := make([]int, n)
		inv := make([]int, n)
		time := 0
		type pair struct{ u, h int }
		stk := make([]pair, 0, n)
		stk = append(stk, pair{0, 0})
		for len(stk) > 0 {
			p := stk[len(stk)-1]
			stk = stk[:len(stk)-1]
			u := p.u
			h := p.h
			for v := u; v != -1; v = heavy[v] {
				head[v] = h
				pos[v] = time
				inv[time] = v
				time++
				for _, c := range adj[v] {
					if c == parent[v] || c == heavy[v] {
						continue
					}
					stk = append(stk, pair{c, c})
				}
			}
		}
		base := make([]int, n)
		for i := 0; i < n; i++ {
			base[pos[i]] = a[i]
		}
		seg := NewSegTree(base)

		type Seg struct {
			l, r int
			dir  int // +1 left->right, -1 right->left
			orv  int
			len  int
		}

		getPathSegs := func(u, v int) ([]Seg, int, []int, []int) {
			upParts := make([]Seg, 0, 32)
			downParts := make([]Seg, 0, 32)
			uu, vv := u, v
			for head[uu] != head[vv] {
				if depth[head[uu]] >= depth[head[vv]] {
					upParts = append(upParts, Seg{l: pos[head[uu]], r: pos[uu], dir: -1})
					uu = parent[head[uu]]
				} else {
					downParts = append(downParts, Seg{l: pos[head[vv]], r: pos[vv], dir: +1})
					vv = parent[head[vv]]
				}
			}
			segs := make([]Seg, 0, len(upParts)+len(downParts)+1)
			for i := 0; i < len(upParts); i++ {
				segs = append(segs, upParts[i])
			}
			if depth[uu] >= depth[vv] {
				segs = append(segs, Seg{l: pos[vv], r: pos[uu], dir: -1})
			} else {
				segs = append(segs, Seg{l: pos[uu], r: pos[vv], dir: +1})
			}
			for i := len(downParts) - 1; i >= 0; i-- {
				segs = append(segs, downParts[i])
			}
			total := 0
			prefix := make([]int, len(segs)+1)
			for i := 0; i < len(segs); i++ {
				if segs[i].l <= segs[i].r {
					segs[i].len = segs[i].r - segs[i].l + 1
				} else {
					segs[i].len = segs[i].l - segs[i].r + 1
				}
				segs[i].orv = seg.QueryOr(min(segs[i].l, segs[i].r), max(segs[i].l, segs[i].r))
				total += segs[i].len
				prefix[i+1] = total
			}
			// suffix for reversed distance from y
			suffix := make([]int, len(segs)+1)
			for i := len(segs) - 1; i >= 0; i-- {
				suffix[i] = suffix[i+1] + segs[i].len
			}
			return segs, total, prefix, suffix
		}

		q := in.NextInt()
		for ; q > 0; q-- {
			x := in.NextInt() - 1
			y := in.NextInt() - 1
			segs, totalNodes, prefix, suffix := getPathSegs(x, y)
			fullOr := 0
			for i := 0; i < len(segs); i++ {
				fullOr |= segs[i].orv
			}
			B := bits.OnesCount(uint(fullOr))
			events := make([][2]int, 0, 64)
			for b := 0; b < 31; b++ {
				if ((fullOr >> b) & 1) == 0 {
					continue
				}
				// find first occurrence from x
				dL := 0
				found := false
				for i := 0; i < len(segs); i++ {
					if ((segs[i].orv >> b) & 1) == 0 {
						continue
					}
					l, r := segs[i].l, segs[i].r
					var idx int
					if segs[i].dir == +1 {
						if l <= r {
							idx = seg.FindFirstLeft(l, r, b)
						} else {
							idx = seg.FindFirstLeft(r, l, b)
						}
						if l > r {
							// reversed l,r in query; idx is in [r,l]
							// map to original interval indices
							// but offset formula uses l as min; keep consistent by rebuilding l=min(l,r)
							l2 := min(l, r)
							dL = prefix[i] + (idx - l2)
							found = true
							break
						}
						dL = prefix[i] + (idx - l)
					} else { // dir == -1
						if l <= r {
							idx = seg.FindFirstRight(l, r, b)
							dL = prefix[i] + (r - idx)
						} else {
							idx = seg.FindFirstRight(r, l, b)
							// original interval [l,r] with l>r, dir -1, nodes count len = l-r+1
							// when querying [r,l], rightmost idx corresponds to original closer to r side (which is smaller index in original)
							// offset from start of segment in original order (from l down to r) equals (l - idx)
							dL = prefix[i] + (l - idx)
						}
					}
					found = true
					break
				}
				if !found {
					// should not happen since bit is in fullOr
					continue
				}
				// find last occurrence from y (scan reversed)
				dFromY := 0
				found = false
				for i := len(segs) - 1; i >= 0; i-- {
					if ((segs[i].orv >> b) & 1) == 0 {
						continue
					}
					l, r := segs[i].l, segs[i].r
					var idx int
					if segs[i].dir == +1 {
						// reversed direction: search from right -> left
						if l <= r {
							idx = seg.FindFirstRight(l, r, b)
							dFromY = suffix[i+1] + (r - idx)
						} else {
							idx = seg.FindFirstRight(r, l, b)
							// original had l>r with dir +1? impossible; dir +1 implies l<=r
							dFromY = suffix[i+1] + (l - idx)
						}
					} else { // dir == -1
						// reversed direction: search from left -> right
						if l <= r {
							idx = seg.FindFirstLeft(l, r, b)
							dFromY = suffix[i+1] + (idx - l)
						} else {
							idx = seg.FindFirstLeft(r, l, b)
							// original l>r, dir -1 valid
							// when querying [r,l], leftmost idx corresponds to original closer to l side
							// distance from y side counts from end of path, which aligns with segments after i plus offset within this segment from its end (original r side)
							// For original dir -1, reversed offset equals idx - r
							dFromY = suffix[i+1] + (idx - r)
						}
					}
					found = true
					break
				}
				if !found {
					continue
				}
				dR := (totalNodes - 1) - dFromY
				events = append(events, [2]int{dL, 1})
				events = append(events, [2]int{dR + 1, -1})
			}
			if len(events) == 0 {
				fmt.Fprintln(out, B)
				continue
			}
			sort.Slice(events, func(i, j int) bool {
				if events[i][0] == events[j][0] {
					return events[i][1] > events[j][1]
				}
				return events[i][0] < events[j][0]
			})
			cur := 0
			best := 0
			idx := 0
			for idx < len(events) {
				p := events[idx][0]
				sum := 0
				for idx < len(events) && events[idx][0] == p {
					sum += events[idx][1]
					idx++
				}
				cur += sum
				if p < totalNodes && cur > best {
					best = cur
				}
			}
			fmt.Fprintln(out, B+best)
		}
	}
}

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
}