Yes, you’re right about the negative numbers, I didn’t account for that, I will refactor. But with all positive numbers I don’t get any errors when I run it in repl.it, but freeCodeCamp editor gives me a TypeError: unknown: Cannot read property '0' of undefined error.
UPDATE
Oh, I see what you mean. That’s weird, I use one-liners all the time, never had a problem with it.
UPDATE 2
Just had to change the count assignment line, everything works with the negative numbers, too now: let count = arr[i][0];