#include <bits/stdc++.h>
using namespace std;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define FOR(i, begin, end) for(int i=(begin);i<(end);i++)
#define REP(i, n) FOR(i,0,n)
#define IFOR(i, begin, end) for(int i=(end)-1;i>=(begin);i--)
#define IREP(i, n) IFOR(i,0,n)
#define Sort(v) sort(v.begin(), v.end())
#define Reverse(v) reverse(v.begin(), v.end())
#define all(v) v.begin(),v.end()
#define SZ(v) ((int)v.size())
#define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x))
#define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x))
#define Max(a, b) a = max(a, b)
#define Min(a, b) a = min(a, b)
#define bit(n) (1LL<<(n))
#define bit_exist(x, n) ((x >> n) & 1)
#define Ans(f, y, n) if(f) cout << y << endl; else cout << n << endl;
#define debug(x) cout << #x << "=" << x << endl;
#define vdebug(v) cout << #v << "=" << endl; REP(i, v.size()){ cout << v[i] << ","; } cout << endl;
#define mdebug(m) cout << #m << "=" << endl; REP(i, m.size()){ REP(j, m[i].size()){ cout << m[i][j] << ","; } cout << endl;}
#define pb push_back
#define f first
#define s second
#define int long long
#define INF 1000000000000000000

using vec = vector<int>;
using mat = vector<vec>;
using Pii = pair<int, int>;
using PiP = pair<int, Pii>;
using PPi = pair<Pii, int>;
using bools = vector<bool>;
using pairs = vector<Pii>;

template<typename T> void readv(vector<T> &a){ REP(i, a.size()) cin >> a[i]; }
void readv_m1(vector<int> &a){ REP(i, a.size()){cin >> a[i]; a[i]--;} }

//int dx[4] = {1,0,-1,0};
//int dy[4] = {0,1,0,-1};

int mod = 1000000007;
//int mod = 998244353;
#define Add(x, y) x = (x + (y)) % mod
#define Mult(x, y) x = (x * (y)) % mod

int yakusuu(int x, vec &prime){
    int n = 1;
    for(int p: prime){
        int k = 0;
        while(x % p == 0){
            k++;
            x /= p;
        }
        n *= k + 1;
    }
    return n;
}

signed main(){

    vec prime;
    FOR(i, 2, 316){
        bool f = true;
        FOR(j, 2, i) if(i % j == 0) f = false;
        if(f) prime.pb(i);
    }

    int N, K; cin >> N >> K;
    map<int, int> m;
    int N0 = N;
    FOR(i, 2, N + 1){
        while(N0 % i == 0){
            m[i] += 1;
            N0 /= i;
        }
    }
    int ans, n = 0;
    FOR(i, 1, N){
        int c = 0;
        int i0 = i;
        for(auto p: m){
            REP(k, p.s){
                if(i0 % p.f == 0){
                    c++;
                    i0 /= p.f;
                }
            }
        }
        int y = yakusuu(i, prime);
        if(c >= K && y > n){
            n = y;
            ans = i;
        }
    }
    cout << ans << endl;

    return 0;
}