#include <iostream>
#include <vector>
#include <set>

using namespace std;

int n, k;
vector<int> vec[100005];
int prime[100005];
multiset<int> S[100005];

int main(void)
{
	for(int i = 2; i < 100005; i++){
		if(prime[i]) continue;
		for(int j = 2*i; j < 100005; j += i){
			prime[j] = i;
		}
	}
	
	cin >> n >> k;
	for(int i = 1; i <= n; i++){
		for(int j = 1; i*j <= n; j++) vec[i*j].push_back(i);
	}
	for(int i = 2; i <= n; i++){
		int t = i;
		while(1){
			int p = prime[t];
			if(p == 0){
				S[i].insert(t);
				break;
			}
			else{
				S[i].insert(p);
				t /= p;
			}
		}
	}
	
	int ans = 0, mx = 0;
	for(int i = 1; i < n; i++){
		int cnt = 0, t = n;
		for(auto x : S[i]){
			if(t % x == 0) cnt++, t /= x;
		}
		if(cnt < k) continue;
		if(mx < vec[i].size()){
			mx = vec[i].size();
			ans = i;
		}
	}
	cout << ans << endl;
	
	return 0;
}