input: from typing import List
  
  def create_3_layer_neural_network(input_layer: List[float], hidden_layer: List[List[float]], output_layer: List[float]) -> List[float]:
      """ Create a 3-layer artificial neural network and compute the output.
      >>> create_3_layer_neural_network([2.0, 3.0], [[0.1, 0.4], [0.8, 0.6], [0.3, 0.9]], [0.3, 0.7])
      [0.71]
      """
output:     hidden_output = []
      for neuron in hidden_layer:
          neuron_output = sum(w * x for w, x in zip(neuron, input_layer))
          hidden_output.append(neuron_output)
      
      final_output = sum(w * x for w, x in zip(output_layer, hidden_output))
      
      return [final_output]