const binarySearch (list, value) => {
  let start = 0
  let stop = list.length - 1
  let middle = Math.floor((start + stop) / 2)

  while (list[middle] !== value && start < stop) {
    if (value < list[middle]) {
      stop = middle - 1
    } else {
      start = middle + 1
    }
    middle = Math.floor((start + stop) / 2)
  }
  return (list[middle] !== value) ? -1 : middle
}
// returns the index of the item or -1 if not found