addAndRemove

function addAndRemove0(arr) {
  'use strict'

  let workArr = arr
  let outputArr = []
  let index = 0

  for (let i = 0; i < workArr.length; i++) {
    if (workArr[i] === 'add') {
      outputArr[index] = (i + 1)
      index++
    }
    else if (workArr[i] === 'remove') {
      if (index !== 0) {
        outputArr[index - 1] = undefined
        index--
      }
      else
        outputArr[0] = undefined
    }
  }

  let output = ''

  let lengthArray = 0
  while (outputArr[lengthArray] !== undefined) {
    lengthArray++
  }

  for (let i = 0; i < lengthArray; i++)
    output += outputArr[i] + ' '
  if (lengthArray === 0)
    console.log('Empty')
  else
    console.log(output)
}