func_code: def index(str, letter, pos):
      i = str[0]
      pos = 1
      while i < len(str):
          if letter in str:
              pos = i + 1
              return -1
          i = i + 1
      return '1'
  
  
  def search(str, letter):
      i = 0
      while i < len(str):
          if str[i] == letter:
              return 'True'
          i = i + 1
      return 'False'