text: class FeedforwardNeuralNetwork:
  
      def __init__(self, input_size, output_size, hidden_layers):
          '''Initializes a FNN with the given input, output and
          hidden layers configuration
  
          Arguments:
              input_size: integer corresponding to the number of units
                  on the input layer
              output_size: integer corresponding to the number of units
                  on the output layer
              hidden_layers: a dictionary of the form 'layerNumber: n units'
                  corresponding to the hidden layers configuration. Each unit
                  is a single perceptron
  
          '''
          self.input_size = input_size
          self.output_size = output_size
          self.hidden = hidden_layers
  