input: Write a python function to perform basic arithmetic operations using the SimpleCalculator class.
  assert SimpleCalculator().add(10, 5) == 15
  assert SimpleCalculator().subtract(10, 5) == 5
  assert SimpleCalculator().multiply(10, 5) == 50
  assert SimpleCalculator().divide(10, 5) == 2.0
output: class SimpleCalculator:
      def add(self, a, b):
          return a + b
  
      def subtract(self, a, b):
          return a - b
  
      def multiply(self, a, b):
          return a * b
  
      def divide(self, a, b):
          return a / b