#include <bits/stdc++.h>


using namespace std;
typedef long long ll;
#define REP(i,n) for(int i=0; i<int(n); i++)
#define FOR(i,m,n) for(int i=int(m); i<int(n); i++)
#define ALL(obj) (obj).begin(),(obj).end()
#define VI vector<int>
#define VLL vector<long long>
#define VVI vector<vector<int>>
#define VVLL vector<vector<long long>>
#define VC vector<char>
#define VS vector<string>
#define VVC vector<vector<char>>
#define VB vector<bool>
#define VVB vector<vector<bool>>
#define fore(i,a) for(auto &i:a)

typedef pair <int, int> P;
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }
const int  INF = 1 << 29;
const ll INFL = 1LL << 60;
const ll mod = 1000000007;





int main() {
	
	int n, k;
	cin >> n >> k;
	VI a(100005);
	int ma = 100005;
	REP(i, ma)a[i] = i;

	for (int i = 2; i < ma; i++) {
		if (a[i] == i) {
			for (int j = 2; i*j < ma; j++) {
				if (a[i*j] == i * j)a[i*j] = i;
			}
		}
	}
	int nn = n;
	map<int,int> m;
	while (nn > 1) {
		m[a[nn]]++;
		nn /= a[nn];
	}
	int ans = INF;
	int an = 0;

	FOR(i, 2, n) {
		int cnt = 0;
		int cn = 1;
		int j = i;
		while (j > 1) {
			int b = 0;
			int c = a[j];
			while (j%c == 0) {
				b++;
				j /= c;
			}
			cnt += min(m[c], b);
			cn *= b + 1;

		}
		if (cnt >= k) {
			if (cn > an) {
				an = cn;
				ans = i;
			}
		}
	}
	cout << ans << endl;
	

}