output_description: If the coins add up to X yen or more, print `Yes`; otherwise, print `No`.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      K X
attempt: k, x = int(input()), int(input())
  print("yes") if k * 500 >= x else ("no")
  
problem_description: Statement
  
  Takahashi has K 500-yen coins. (Yen is the currency of Japan.) If these coins
  add up to X yen or more, print `Yes`; otherwise, print `No`.
samples: [{"input": "2 900", "output": "Yes\n    \n\nTwo 500-yen coins add up to 1000 yen, which is not less than X = 900 yen.\n\n* * *"}, {"input": "1 501", "output": "No\n    \n\nOne 500-yen coin is worth 500 yen, which is less than X = 501 yen.\n\n* * *"}, {"input": "4 2000", "output": "Yes\n    \n\nFour 500-yen coins add up to 2000 yen, which is not less than X = 2000 yen."}]