text: import numpy as np
  
  class Sigmoid:
      def __init__(self):
          self.out = None
  
      def forward(self, x):
          out = 1 / (1 + np.exp(-x))
          self.out = out
  
          return out
  
      def backward(self, dout):
          dx = dout * (1.0 - self.out) * self.out
  
          return dx
  
  sigmoid = Sigmoid()
  v1 = sigmoid.forward(100)
  print(v1)
  v2 = sigmoid.backward(v1)
  print(v2)