new_contents: # Import decimal
  from decimal import Decimal
  
  if __name__ == '__main__':
      n = int(input())
      student_marks = {}
      for _ in range(n):
          name, *line = input().split()
          scores = list(map(float, line))
          student_marks[name] = scores
      query_name = input()
      
      # Extract the values into a list: query_scores
      query_scores = student_marks[query_name]
  
      # Sum the scores in the list: total_scores
      total_scores = sum(query_scores)
  
      # Convert the floats to decimals and average the scores: avg
      avg = Decimal(total_scores/3)
  
      # Print the mean of the scores, correct to two decimals
      print(round(avg,2))
  
subject: Create HR_pythonFindingThePercentage.py