The sieve of Eratosthenes is a famous algorithm to find all prime numbers up to \(N\). The algorithm is:

1. Write down all integers between \(2\) and \(N\), inclusive.
2. Find the smallest number not already crossed out and call it \(P\); \(P\) is prime.
3. Cross out \(P\) and all its multiples that aren't already crossed out.
4. If not all numbers have been crossed out, go to step 2.

Write a program that, given \(N\) and \(K\), finds the \(K\)-th integer to be crossed out.

The integers \(N\) and \(K\) (\(2 \le K < N \le 1000\)).

Output the \(K\)-th number to be crossed out.

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출처 COCI 2008/2009 Contest 2