input: Write a python function to determine if a binary sequence is balanced (equal number of 0s and 1s).
  assert is_balanced([0, 1, 0, 1]) == True
  assert is_balanced([0, 0, 1, 1]) == True
  assert is_balanced([0, 1, 1, 0, 1, 0]) == True
  assert is_balanced([0, 1, 1, 1, 0, 0, 0]) == False
output: def is_balanced(sequence):
      return sequence.count(0) == sequence.count(1)