#include <iostream>
#include <vector>
using namespace std;

int main() {
	int n, k, i,j;
	int arr[1001] = { 0 };
	vector<int> p;
	cin >> n >> k;
	for (i = 2; i <= n; i++) {
		arr[i] = i;
	}
	for (i = 2; i <= n; i++) {
		if (arr[i] != 0) {
			p.push_back(i);
			for (j = i * 2; j <= n; j += i) {
				if (arr[j] != 0) {
					p.push_back(j);
					arr[j] = 0;
				}
			}
		}
	}
	cout << p[k - 1] << '\n';
	return 0;
}