import sequtils,algorithm,math,tables
import sets,intsets,queues,heapqueue,bitops,strutils
template times*(n:int,body) = (for _ in 0..<n: body)
template `max=`*(x,y) = x = max(x,y)
template `min=`*(x,y) = x = min(x,y)

proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  while true:
    let k = getchar_unlocked()
    if k < '0': break
    result = 10 * result + k.ord - '0'.ord

proc putchar_unlocked(c:char){. importc:"putchar_unlocked",header: "<stdio.h>" .}
proc printInt(a:int32) =
  if a == 0:
    putchar_unlocked('0')
    return
  template div10(a:int32) : int32 = cast[int32]((0x1999999A * cast[int64](a)) shr 32)
  template mod10(a:int32) : int32 = a - (a.div10 * 10)
  var n = a
  var rev = a
  var cnt = 0
  while rev.mod10 == 0:
    cnt += 1
    rev = rev.div10
  rev = 0
  while n != 0:
    rev = rev * 10 + n.mod10
    n = n.div10
  while rev != 0:
    putchar_unlocked((rev.mod10 + '0'.ord).chr)
    rev = rev.div10
  while cnt != 0:
    putchar_unlocked('0')
    cnt -= 1
proc printInt(a:int,last:char) =
  a.int32.printInt()
  putchar_unlocked(last)


template useBinaryHeap() = # 追加 / 最小値検索 / 最小値Pop O(log(N))
  type
    BinaryHeap*[T] = ref object
      nodes: seq[T]
      compare: proc(x,y:T):int
      popchunk: bool
  proc newBinaryHeap*[T](compare:proc(x,y:T):int): BinaryHeap[T] =
    new(result)
    result.nodes = newSeq[T]()
    result.compare = compare
  proc compareNode[T](h:BinaryHeap[T],i,j:int):int = h.compare(h.nodes[i],h.nodes[j])
  proc size*[T](h:BinaryHeap[T]):int = h.nodes.len() - h.popchunk.int
  proc items*[T](h:var BinaryHeap[T]):seq[T] =
    if h.popchunk : discard h.popimpl()
    return h.nodes
  proc top*[T](h:var BinaryHeap[T]): T =
    if h.popchunk : discard h.popimpl()
    return h.nodes[0]
  proc push*[T](h:var BinaryHeap[T],node:T):void =
    if h.popchunk :
      h.nodes[0] = node
      h.shiftdown()
    else: h.pushimpl(node)
  proc pop*[T](h:var BinaryHeap[T]):T =
    if h.popchunk: discard h.popimpl()
    h.popchunk = true
    return h.nodes[0]

  proc shiftdown[T](h:var BinaryHeap[T]): void =
    h.popchunk = false
    let size = h.nodes.len()
    var i = 0
    while true :
      let L = i * 2 + 1
      let R = i * 2 + 2
      if L >= size : break
      let child = if R < size and h.compareNode(R,L) <= 0 : R else: L
      if h.compareNode(i,child) <= 0: break
      swap(h.nodes[i],h.nodes[child])
      i = child

  proc pushimpl[T](h:var BinaryHeap[T],node:T):void =
    h.nodes.add(node) #末尾に追加
    var i = h.nodes.len() - 1
    while i > 0: # 末尾から木を整形
      let parent = (i - 1) div 2
      if h.compare(h.nodes[parent],node) <= 0: break
      h.nodes[i] = h.nodes[parent]
      i = parent
    h.nodes[i] = node

  proc popimpl[T](h:var BinaryHeap[T]):T =
    result = h.nodes[0] # rootと末尾を入れ替えて木を整形
    h.nodes[0] = h.nodes[^1]
    h.nodes.setLen(h.nodes.len() - 1)
    h.shiftdown()
useBinaryHeap()
proc solve() : int =
  let n = scan()
  let L = newSeqWith(n,scan()).sorted(cmp)
  var R = @[1]
  for i in 1..<n:
    if L[i-1] == L[i] : R[^1] += 1
    else: R &= 1
  if R.len < 3: return
  var q = newBinaryHeap[int](proc(x,y:int):int=y-x)
  for r in R: q.push(r)
  while true:
    let a = q.pop() - 1
    let b = q.pop() - 1
    let c = q.pop() - 1
    if a < 0 or b < 0 or c < 0 : return
    result += 1
    q.push(a)
    q.push(b)
    q.push(c)

scan().times: solve().printInt('\n')