As Hannah explored the Ice Caves, she came across some numbers scrawled on the wall.
The first one was simply "1".
The next, "11".
Then, "21", "1,211", and "111,221".
What was the next number she came across on the cave wall?
Try reading the digits aloud and it might help you. The first one is "one" the second one describes the first one, so it's "one one". The third one describes the second one so it's "two ones". The next one is "one two and two ones". Then "one one one two and two ones". Finally, look at the last answer: "three ones, two twos and one one", or 312,211.