description: The Hat is a game of speedy explanation/guessing words (similar to Alias). It's fun. Try it! In this problem, we are talking about a variant of the game when the players are sitting at the table and everyone plays individually (i.e. not teams, but individual gamers play).
  
  n people gathered in a room with m tables (n ≥ 2m). They want to play the Hat k times. Thus, k games will be played at each table. Each player will play in k games.
  
  To do this, they are distributed among the tables for each game. During each game, one player plays at exactly one table. A player can play at different tables.
  
  Players want to have the most "fair" schedule of games. For this reason, they are looking for a schedule (table distribution for each game) such that:
  
    * At any table in each game there are either ⌊n/m⌋ people or ⌈n/m⌉ people (that is, either n/m rounded down, or n/m rounded up). Different numbers of people can play different games at the same table.
    * Let's calculate for each player the value b_i — the number of times the i-th player played at a table with ⌈n/m⌉ persons (n/m rounded up). Any two values of b_imust differ by no more than 1. In other words, for any two players i and j, it must be true |b_i - b_j| ≤ 1. 
  
  
  
  For example, if n=5, m=2 and k=2, then at the request of the first item either two players or three players should play at each table. Consider the following schedules:
  
    * First game: 1, 2, 3 are played at the first table, and 4, 5 at the second one. The second game: at the first table they play 5, 1, and at the second — 2, 3, 4. This schedule is not "fair" since b_2=2 (the second player played twice at a big table) and b_5=0 (the fifth player did not play at a big table).
    * First game: 1, 2, 3 are played at the first table, and 4, 5 at the second one. The second game: at the first table they play 4, 5, 2, and at the second one — 1, 3. This schedule is "fair": b=[1,2,1,1,1] (any two values of b_i differ by no more than 1). 
  
  
  
  Find any "fair" game schedule for n people if they play on the m tables of k games.
  
  Input
  
  The first line of the input contains an integer t (1 ≤ t ≤ 10^4) — the number of test cases in the test.
  
  Each test case consists of one line that contains three integers n, m and k (2 ≤ n ≤ 2⋅10^5, 1 ≤ m ≤ ⌊n/2⌋, 1 ≤ k ≤ 10^5) — the number of people, tables and games, respectively.
  
  It is guaranteed that the sum of nk (n multiplied by k) over all test cases does not exceed 2⋅10^5.
  
  Output
  
  For each test case print a required schedule — a sequence of k blocks of m lines. Each block corresponds to one game, a line in a block corresponds to one table. In each line print the number of players at the table and the indices of the players (numbers from 1 to n) who should play at this table.
  
  If there are several required schedules, then output any of them. We can show that a valid solution always exists.
  
  You can output additional blank lines to separate responses to different sets of inputs.
  
  Example
  
  Input
  
  
  3
  5 2 2
  8 3 1
  2 1 3
  
  
  Output
  
  
  3 1 2 3
  2 4 5
  3 4 5 2
  2 1 3
  
  2 6 2
  3 3 5 1
  3 4 7 8
  
  2 2 1
  2 2 1
  2 2 1
solution: 
  class SortedList:
      def __init__(self, iterable=[], _load=200):
          """Initialize sorted list instance."""
          values = sorted(iterable)
          self._len = _len = len(values)
          self._load = _load
          self._lists = _lists = [values[i:i + _load] for i in range(0, _len, _load)]
          self._list_lens = [len(_list) for _list in _lists]
          self._mins = [_list[0] for _list in _lists]
          self._fen_tree = []
          self._rebuild = True
  
      def _fen_build(self):
          """Build a fenwick tree instance."""
          self._fen_tree[:] = self._list_lens
          _fen_tree = self._fen_tree
          for i in range(len(_fen_tree)):
              if i | i + 1 < len(_fen_tree):
                  _fen_tree[i | i + 1] += _fen_tree[i]
          self._rebuild = False
  
      def _fen_update(self, index, value):
          """Update `fen_tree[index] += value`."""
          if not self._rebuild:
              _fen_tree = self._fen_tree
              while index < len(_fen_tree):
                  _fen_tree[index] += value
                  index |= index + 1
  
      def _fen_query(self, end):
          """Return `sum(_fen_tree[:end])`."""
          if self._rebuild:
              self._fen_build()
  
          _fen_tree = self._fen_tree
          x = 0
          while end:
              x += _fen_tree[end - 1]
              end &= end - 1
          return x
  
      def _fen_findkth(self, k):
          """Return a pair of (the largest `idx` such that `sum(_fen_tree[:idx]) <= k`, `k - sum(_fen_tree[:idx])`)."""
          _list_lens = self._list_lens
          if k < _list_lens[0]:
              return 0, k
          if k >= self._len - _list_lens[-1]:
              return len(_list_lens) - 1, k + _list_lens[-1] - self._len
          if self._rebuild:
              self._fen_build()
  
          _fen_tree = self._fen_tree
          idx = -1
          for d in reversed(range(len(_fen_tree).bit_length())):
              right_idx = idx + (1 << d)
              if right_idx < len(_fen_tree) and k >= _fen_tree[right_idx]:
                  idx = right_idx
                  k -= _fen_tree[idx]
          return idx + 1, k
  
      def _delete(self, pos, idx):
          """Delete value at the given `(pos, idx)`."""
          _lists = self._lists
          _mins = self._mins
          _list_lens = self._list_lens
  
          self._len -= 1
          self._fen_update(pos, -1)
          del _lists[pos][idx]
          _list_lens[pos] -= 1
  
          if _list_lens[pos]:
              _mins[pos] = _lists[pos][0]
          else:
              del _lists[pos]
              del _list_lens[pos]
              del _mins[pos]
              self._rebuild = True
  
      def _loc_left(self, value):
          """Return an index pair that corresponds to the first position of `value` in the sorted list."""
          if not self._len:
              return 0, 0
  
          _lists = self._lists
          _mins = self._mins
  
          lo, pos = -1, len(_lists) - 1
          while lo + 1 < pos:
              mi = (lo + pos) >> 1
              if value <= _mins[mi]:
                  pos = mi
              else:
                  lo = mi
  
          if pos and value <= _lists[pos - 1][-1]:
              pos -= 1
  
          _list = _lists[pos]
          lo, idx = -1, len(_list)
          while lo + 1 < idx:
              mi = (lo + idx) >> 1
              if value <= _list[mi]:
                  idx = mi
              else:
                  lo = mi
  
          return pos, idx
  
      def _loc_right(self, value):
          """Return an index pair that corresponds to the last position of `value` in the sorted list."""
          if not self._len:
              return 0, 0
  
          _lists = self._lists
          _mins = self._mins
  
          pos, hi = 0, len(_lists)
          while pos + 1 < hi:
              mi = (pos + hi) >> 1
              if value < _mins[mi]:
                  hi = mi
              else:
                  pos = mi
  
          _list = _lists[pos]
          lo, idx = -1, len(_list)
          while lo + 1 < idx:
              mi = (lo + idx) >> 1
              if value < _list[mi]:
                  idx = mi
              else:
                  lo = mi
  
          return pos, idx
  
      def add(self, value):
          """Add `value` to sorted list."""
          _load = self._load
          _lists = self._lists
          _mins = self._mins
          _list_lens = self._list_lens
  
          self._len += 1
          if _lists:
              pos, idx = self._loc_right(value)
              self._fen_update(pos, 1)
              _list = _lists[pos]
              _list.insert(idx, value)
              _list_lens[pos] += 1
              _mins[pos] = _list[0]
              if _load + _load < len(_list):
                  _lists.insert(pos + 1, _list[_load:])
                  _list_lens.insert(pos + 1, len(_list) - _load)
                  _mins.insert(pos + 1, _list[_load])
                  _list_lens[pos] = _load
                  del _list[_load:]
                  self._rebuild = True
          else:
              _lists.append([value])
              _mins.append(value)
              _list_lens.append(1)
              self._rebuild = True
  
      def discard(self, value):
          """Remove `value` from sorted list if it is a member."""
          _lists = self._lists
          if _lists:
              pos, idx = self._loc_right(value)
              if idx and _lists[pos][idx - 1] == value:
                  self._delete(pos, idx - 1)
  
      def remove(self, value):
          """Remove `value` from sorted list; `value` must be a member."""
          _len = self._len
          self.discard(value)
          if _len == self._len:
              raise ValueError('{0!r} not in list'.format(value))
  
      def pop(self, index=-1):
          """Remove and return value at `index` in sorted list."""
          pos, idx = self._fen_findkth(self._len + index if index < 0 else index)
          value = self._lists[pos][idx]
          self._delete(pos, idx)
          return value
  
      def bisect_left(self, value):
          """Return the first index to insert `value` in the sorted list."""
          pos, idx = self._loc_left(value)
          return self._fen_query(pos) + idx
  
      def bisect_right(self, value):
          """Return the last index to insert `value` in the sorted list."""
          pos, idx = self._loc_right(value)
          return self._fen_query(pos) + idx
  
      def count(self, value):
          """Return number of occurrences of `value` in the sorted list."""
          return self.bisect_right(value) - self.bisect_left(value)
  
      def __len__(self):
          """Return the size of the sorted list."""
          return self._len
  
      def __getitem__(self, index):
          """Lookup value at `index` in sorted list."""
          pos, idx = self._fen_findkth(self._len + index if index < 0 else index)
          return self._lists[pos][idx]
  
      def __delitem__(self, index):
          """Remove value at `index` from sorted list."""
          pos, idx = self._fen_findkth(self._len + index if index < 0 else index)
          self._delete(pos, idx)
  
      def __contains__(self, value):
          """Return true if `value` is an element of the sorted list."""
          _lists = self._lists
          if _lists:
              pos, idx = self._loc_left(value)
              return idx < len(_lists[pos]) and _lists[pos][idx] == value
          return False
  
      def __iter__(self):
          """Return an iterator over the sorted list."""
          return (value for _list in self._lists for value in _list)
  
      def __reversed__(self):
          """Return a reverse iterator over the sorted list."""
          return (value for _list in reversed(self._lists) for value in reversed(_list))
  
      def __repr__(self):
          """Return string representation of sorted list."""
          return 'SortedList({0})'.format(list(self))
  
  class OrderedList(SortedList): #Codeforces, Ordered Multiset
      def __init__(self, arg):
          super().__init__(arg)
      def rangeCountByValue(self, leftVal, rightVal): #returns number of items in range [leftVal,rightVal] inclusive
          leftCummulative = self.bisect_left(leftVal)
          rightCummulative = self.bisect_left(rightVal + 1)
          return rightCummulative - leftCummulative
  
  def solve():
      n, m, k = readIntArr()
      
      # assume n % m != 0
      smallPeople = n // m # number of people at smallTable
      largePeople = smallPeople + 1
      smallTable = largePeople * m - n # number of small Tables
      largeTable = m - smallTable
      # print('smallPeople:{} largePeople:{} smallTable:{} largeTable:{}'.format(
      #     smallPeople, largePeople, smallTable, largeTable))
      
      playerCnts = SortedList([(0, i) for i in range(1, n + 1)]) # (b, player)
      ans = []
      for roundd in range(k):
          # print('round:{} playerCnts:{}'.format(roundd, playerCnts))
          playerCnts2 = SortedList()
          # fill large tables first
          for _ in range(largeTable):
              sz = largePeople
              arr = [sz]
              for __ in range(sz):
                  b, player = playerCnts.pop(0)
                  arr.append(player)
                  playerCnts2.add((b + 1, player))
              ans.append(arr)
          # fill small tables
          for _ in range(smallTable):
              sz = smallPeople
              arr = [sz]
              for __ in range(sz):
                  b, player = playerCnts.pop(-1)
                  arr.append(player)
                  playerCnts2.add((b, player))
              ans.append(arr)
          playerCnts = playerCnts2
          ans.append([''])
      multiLineArrayOfArraysPrint(ans)
  
  def main():
      
      t = int(input())
      for _ in range(t):
          solve()
          print()
      
      return
  
  
  import sys
  input=sys.stdin.buffer.readline #FOR READING PURE INTEGER INPUTS (space separation ok)
  # input=lambda: sys.stdin.readline().rstrip("\r\n") #FOR READING STRING/TEXT INPUTS.
  
  def oneLineArrayPrint(arr):
      print(' '.join([str(x) for x in arr]))
  def multiLineArrayPrint(arr):
      print('\n'.join([str(x) for x in arr]))
  def multiLineArrayOfArraysPrint(arr):
      print('\n'.join([' '.join([str(x) for x in y]) for y in arr]))
   
  def readIntArr():
      return [int(x) for x in input().split()]
  # def readFloatArr():
  #     return [float(x) for x in input().split()]
   
  def makeArr(defaultValFactory,dimensionArr): # eg. makeArr(lambda:0,[n,m])
      dv=defaultValFactory;da=dimensionArr
      if len(da)==1:return [dv() for _ in range(da[0])]
      else:return [makeArr(dv,da[1:]) for _ in range(da[0])]
   
  def queryInteractive(a, b, c):
      print('? {} {} {}'.format(a, b, c))
      sys.stdout.flush()
      return int(input())
   
  def answerInteractive(ansArr):
      print('! {}'.format(' '.join([str(x) for x in ansArr])))
      sys.stdout.flush()
   
  inf=float('inf')
  # MOD=10**9+7
  # MOD=998244353
  
  from math import gcd,floor,ceil
  import math
  # from math import floor,ceil # for Python2
   
  for _abc in range(1):
      main()