Each line will be a link to a problem. To earn a grade, you need to complete one problem from that rung of the ladder. But! Since you can’t really reach the top of a ladder in one step (and I’m assuming many of you will want to reach for the top step), you must also complete one problem from each of the four rungs below the top rung you reach.
In other words, you’ll earn the grade at the top of the highest set of 5 sequential challenges that you successfully solve. Note: even though there are multiple challenges offered at a rung, you only need to solve one challenge to qualify for that rung.
For example, using the ladder to the left, I could choose to solve Once upon a Cigol Night, Nekorb hills, Lullaby dreams, Turtle power and The grand tree. That would qualify me for the A- on this ladder. (This one’s only an example, though.)