h2j24

    class Answer {
        getAnswer(input: number) { return (input * 6 + 4) / 2; }
    }

    interface Operation<T> {
        apply(input: T);
    }

    class Addition implements Operation<Number> {
    }
    class Multiplication implements Operation<Number> {
    }
    class Division implements Operation<Number> {
    }

    function compose(Operation<T>... operation, T input) {
        T last = input;
        for (Operation<T> op : operations) {
            last = op.apply(last);
        }
        return last;
    }

    class Adder {
        base: number;
        constructor(base: number) { this.base = base; }
        add(o: number): number { return this.base + o; }
    }