function createCounter() {
  let count = 0;
  
  return {
    increment() {
      count++;
      return count;
    },
    decrement() {
      count--;
      return count;
    },
    getValue() {
      return count;
    }
  };
}

const counter1 = createCounter();
const counter2 = createCounter();

counter1.increment();
counter1.increment();
counter2.increment();
counter1.decrement();

console.log(counter1.getValue() + counter2.getValue());