input: def rounded_average_binary(n, m):
      """Given two positive integers n and m, calculate the mean of
      all integers from n to m, inclusive. 
      Round the result to the closest whole number and represent it in binary form.
      If n exceeds m, return -1.
      Examples:
      rounded_average_binary(1, 5) => "0b11"
      rounded_average_binary(7, 5) => -1
      rounded_average_binary(10, 20) => "0b1111"
      rounded_average_binary(20, 33) => "0b11010"
      """
output:     
      if n > m:
          return -1
      total = sum(range(n, m + 1))
      count = m - n + 1
      average = total / count
      rounded_average = round(average)
      return bin(rounded_average)
  