#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int N,K;
main()
{
	cin>>N>>K;
	int sn=N;
	vector<int>a;
	for(int i=2;i*i<=N;i++)
	{
		while(N%i==0)
		{
			a.push_back(i);
			N/=i;
		}
	}
	if(N>1)a.push_back(N);
	vector<int>x;
	for(int comb=(1<<K)-1;comb<1<<a.size();)
	{
		int now=1;
		for(int j=0;j<a.size();j++)
		{
			if(comb>>j&1)
			{
				now*=a[j];
			}
		}
		x.push_back(now);
		int X=comb&-comb;
		int y=comb+X;
		comb=(comb&~y)/X>>1|y;
	}
	sort(x.begin(),x.end());
	x.erase(unique(x.begin(),x.end()),x.end());
	int M,am=0;
	for(int i=1;i<sn;i++)
	{
		bool f=0;
		for(int j=0;j<x.size();j++)
		{
			if(i%x[j]==0)
			{
				f=1;
				break;
			}
		}
		if(!f)continue;
		int cnt=1,now=i;
		for(int j=2;j*j<=now;j++)
		{
			if(now%j==0)
			{
				int ac=1;
				while(now%j==0)
				{
					now/=j;
					ac++;
				}
				cnt*=ac;
			}
		}
		if(now>1)cnt*=2;
		if(am<cnt)am=cnt,M=i;
	}
	cout<<M<<endl;
}