input: def removeDuplicates(arr):
   result = [] 
    
   # traverse for all elements 
   for i in arr: 
    
    # check if exists in result 
    if i not in result: 
     result.append(i) 
    
   # return result 
   return result
  
  # Example:
  # >>> removeDuplicates(['a', 'b', 'a', 'c', 'c', 'd'])
  # ['a', 'b', 'c', 'd']
  # 
output:     return result