input: import numpy as np
  
  def runningTotal(arr):
      """ Given a list of numbers, return an array with the running total of numbers.
      >>> runningTotal([1, 2, 3, 4])
      array([1, 3, 6, 10])
      >>> runningTotal([0, 1, -1, 2, -2])
      array([0, 1, 0, 2, 0])
      """
      return np.cumsum(arr)
output:     return np.cumsum(arr)