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 (2 ≤ K < N ≤ 1000).

출력

Output the K-th number to be crossed out.

예제 입력 1

7 3

예제 출력 1

6

예제 입력 2

15 12

예제 출력 2

7

예제 입력 3

10 7

예제 출력 3

9