# python3

class HeapBuilder:
  def __init__(self):
    self._swaps = []
    self._data = []

  def ReadData(self):
    n = int(input())
    self._data = [int(s) for s in input().split()]
    assert n == len(self._data)

  def WriteResponse(self):
    #print(self._data)
    print(len(self._swaps))
    for swap in self._swaps:
      print(swap[0], swap[1])

  def left(self,i):
    if i*2+1 >= len(self._data):
      return -1

    return i*2+1

  def write(self, i):
    if i * 2 + 2 >= len(self._data):
      return -1

    return i * 2 + 2

  def heapfy(self,i):
    minindex = i
    if self.left(i) != -1 and self._data[self.left(i)] < self._data[minindex]:
      minindex = self.left(i)
    if self.write(i)!=-1 and self._data[self.write(i)]<self._data[minindex]:
      minindex = self.write(i)
    if minindex !=i:
      self._swaps.append((i,minindex))
      self._data[i],self._data[minindex] = self._data[minindex],self._data[i]

      self.heapfy(minindex)

  def GenerateSwaps(self):
     for x in range(len(self._data)//2, -1 , -1):
       self.heapfy(x)



  def Solve(self):
    self.ReadData()
    self.GenerateSwaps()
    self.WriteResponse()

if __name__ == '__main__':
    heap_builder = HeapBuilder()
    heap_builder.Solve()