input: 
  def evaluate_postfix(expression: str) -> int:
      """
      Evaluate a given postfix expression. The expression is a string with space-separated tokens.
      Each token can be either an operand (a number) or an operator (+, -, *, /).
      >>> evaluate_postfix("2 3 + 4 5 * *")
      46
      >>> evaluate_postfix("5 3 - 4 *")
      8
      """
      tokens = expression.split()
      stack = []
      
      for token in tokens:
          if token.isdigit():
              stack.append(int(token))
          else:
              b = stack.pop()
              a = stack.pop()
              if token == '+':
                  stack.append(a + b)
              elif token == '-':
                  stack.append(a - b)
              elif token == '*':
                  stack.append(a * b)
              elif token == '/':
                  stack.append(a / b)
      
      return stack[0]
  
  # Example usage:
  expression = "2 3 + 4 5 * *"
  print(evaluate_postfix(expression))  # Output: 46
  
output:     tokens = expression.split()
      stack = []
      
      for token in tokens:
          if token.isdigit():
              stack.append(int(token))
          else:
              b = stack.pop()
              a = stack.pop()
              if token == '+':
                  stack.append(a + b)
              elif token == '-':
                  stack.append(a - b)
              elif token == '*':
                  stack.append(a * b)
              elif token == '/':
                  stack.append(a / b)
      
      return stack[0]