Your task is to implement class SmartCalculator. All methods in class should be chainable. The priority of different operations should be kept in mind. It means, that 2 2 * 2 is 6, not 8.

For example:

  const calculator = new SmartCalculator(2);

  const value = calculator
    .add(2)
    .multiply(2);

  console.log(value); // 6

Constructor should take initial value. Be sure, that all tests work with integers. Write your solution in src/index.js