All test cases except the default one resulted in time out, so I decided to get test case #1 in exchange for some hackos.

But when I copy pasted the test case as custom input, I got the message:

"Sorry, we can't accept your submission. The custom input size should not exceed 50Kb."

The input starts with

500000 644 (500'000 lines of input and 644 as cache size)

So, HackerRank, please make it consistent, and allow custom test cases as big as the ones in the evaluation.