code: def iterative(s):
      r = list(s)
      i, j = 0, len(s) - 1
      while i < j:
          r[i], r[j] = r[j], r[i]
          i += 1
          j -= 1
      return "".join(r)
  
label_desc: Use image node_id 2 for calling a global function with example usage: iterative(s) and returns: str