RESETO

문제

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, find the K-th integer to be crossed out. 

입력

The integers N and K (1 ≤ K < N, max(1, K) < N ≤ 1000).

 

출력

Output the K-th number to be crossed out.

힌트

In the third example, we cross out, in order, the numbers 2, 4, 6, 8, 10, 3, 9, 5 and 7. The seventh number is 9.

7 3

6

15 12

7

10 7

9