input: Write a python function to calculate BMI (Body Mass Index) given height in centimeters and weight in kilograms.
  assert round(calculate_bmi(170, 70), 2) == 24.22
  assert round(calculate_bmi(160, 50), 2) == 19.53
  assert round(calculate_bmi(180, 90), 2) == 27.78
output: def calculate_bmi(height_cm, weight_kg):
      height_m = height_cm / 100
      bmi = weight_kg / (height_m ** 2)
      return bmi