output_description: Print `YES` if there is a possibility that Takahashi can participate in the
  next tournament, and print `NO` otherwise.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      S
attempt: print("No" if input().count("x") >= 8 else "Yes")
  
problem_description: Statement
  
  Takahashi is competing in a sumo tournament. The tournament lasts for 15 days,
  during which he performs in one match per day. If he wins 8 or more matches,
  he can also participate in the next tournament.
  
  The matches for the first k days have finished. You are given the results of
  Takahashi's matches as a string S consisting of `o` and `x`. If the i-th
  character in S is `o`, it means that Takahashi won the match on the i-th day;
  if that character is `x`, it means that Takahashi lost the match on the i-th
  day.
  
  Print `YES` if there is a possibility that Takahashi can participate in the
  next tournament, and print `NO` if there is no such possibility.
samples: [{"input": "oxoxoxoxoxoxox", "output": "YES\n    \n\nTakahashi has 7 wins and 7 losses before the last match. If he wins that\nmatch, he will have 8 wins.\n\n* * *"}, {"input": "xxxxxxxx", "output": "NO"}]