2960.java

import java.util.*;

public class Main {

 public static void main(String[] args) {

 Scanner sc = new Scanner(System.in);

 int n = sc.nextInt();
 int k = sc.nextInt();
 int delCnt = 0;

 boolean[] arr = new boolean[n+1];
 Arrays.fill(arr, true);

 for(int i=2; i<=n; i++) {
 if(arr[i]) {
 int num = 0;
 while(++num <= n) {
 if (num * i < arr.length && arr[num * i]) {
 arr[num * i] = false;
 if (++delCnt == k) {
 System.out.println(num * i);
 System.exit(0);
 }
 }
 }
 }
 }
 }
}