Lexi Yash

Yash likes to play around with strings. Once, Yash’s friend decides to play a string game with Yash. Yash is assigned with a string $S$ of only lowercase alphabets with length $N$. He needs to first find all the substrings of $S$ and then find lexicographically $Kth$ smallest substring. Yash wins the string game if he computes correct hash value H of the substring. $H$ is calculated using the hash