#include<iostream>
#include<vector>
#include<string>
#include<cmath>
#include<algorithm>
#include<functional>
#include<numeric>
#include<queue>
#include<stack>
#include<map>
#include<unordered_map>
#include<set>
#include<bitset>
#include<random>

#pragma region
using namespace std;
#define FOR(i,r,n) for(ll i = (ll)(r); i < (ll)(n); i++)
#define rep(i,n) FOR(i,0LL,n)
#define RFOR(i,r,n) for(ll i=(ll)(n-1);i>=r;i--)
#define rrep(i,n) RFOR(i,0LL,n)
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define COUNT(a,y,x) upper_bound(all(a), y) - lower_bound(all(a), x)
#define UNIQUE(a) sort(all(a)); a.erase(unique(all(a)), a.end())
#define pb push_back
typedef int ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef pair<ll, ll> pll;
typedef vector<pll> vpll;
typedef vector<string> vs;
typedef map<ll, ll> MAP;
const ll inf = 2222222222222222222LL;
const ll mod = 1000000007LL;

ll n = 0, m = 0, ans = 0, tmp = 0, ma = -inf, mi = inf;
string s;
bool ok;
ll dx[9] = { 0,1,-1,0,0,1,1,-1,-1 }, dy[9] = { 0,0,0,1,-1,1,-1,1,-1 };
#define endl '\n'
#pragma endregion
#define MAX 222222



vvll dvs;

void divosor(ll N = MAX) {
  rep(i, N + 1) dvs.emplace_back();
  FOR(i, 1, N + 1) {
    for (ll j = i; j <= N; j += i) {
      dvs[j].pb(i);
    }
  }
}

vpll factorize(ll val) {
  vpll ret;
  for (ll i = 2; i*i <= val; i++) {
    if (!(val%i)) {
      ll fcnt = 0;
      while (!(val%i)) {
        val /= i;
        fcnt++;
      }
      ret.pb(make_pair(i, fcnt));
    }
  }
  if (val != 1) ret.pb(make_pair(val, 1));
  return ret;
}


int main(void) {
  ios::sync_with_stdio(false); cin.tie(0);


  cin >> n >> m;
  divosor(n);
  vpll fac = factorize(n);
  RFOR(i, 1, n) {
    ll cnt = 0, cur = i;
    rep(j, fac.size()) {
      rep(k, fac[j].second) {
        if (cur%fac[j].first == 0) {
          cur /= fac[j].first;
          cnt++;
        }
        else break;
      }
    }
    if (cnt < m || (ll)dvs[i].size() < ma) continue;
    ma = max(ma, (ll)dvs[i].size());
    ans = i;
  }

  cout << ans << endl;

  return 0;
}