output_description: If all the characters in S are different, print `yes` (case-sensitive);
  otherwise, print `no`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: 
  S= input()
  B=set(S)
  ​
  if len(S)==len(B):
    print("yes")
    
  else:
    print("no")
    
problem_description: Statement
  
  You are given a string S consisting of lowercase English letters. Determine
  whether all the characters in S are different.
samples: [{"input": "uncopyrightable", "output": "yes\n    \n\n* * *"}, {"input": "different", "output": "no\n    \n\n* * *"}, {"input": "no", "output": "yes"}]