#include <bits/stdc++.h>

using namespace std;

using ll = long long;

bool is_prime(int n) {
    if (n % 2 == 0) return false;
    for (int i = 2; i * i <= n; i++) {
        if (n % i == 0) return false;
    }
    return n != 1;
}

vector<int> divisor(int n) {
    vector<int> res;
    for (int i = 1; i * i <= n; i++) {
        if (n % i == 0) {
            res.emplace_back(i);
            if (i != n / i) res.emplace_back(n / i);
        }
    }
    return res;
}

map<int, int> prime_factor(int n) {
    map<int, int> res;
    for (int i = 2; i * i <= n; i++) {
        while (n % i == 0) {
            ++res[i];
            n /= i;
        }
    }
    if (n != 1) res[n] = 1;
    return res;
}

vector<int> sieve(int n) {
    vector<int> res;
    vector<bool> is_prime(n + 1, true);
    is_prime[0] = false;
    is_prime[1] = false;
    for (int i = 2; i <= n; i++) {
        if (!is_prime[i]) continue;
        res.emplace_back(i);
        for (int j = 2 * i; j <= n; j += i) is_prime[j] = false;
    }
    return res;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, K;
    cin >> n >> K;
    map<int, int> memo = prime_factor(n);

    int max_num = 0;
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        map<int, int> memo2 = prime_factor(i);
        int cnt = 0;
        for (auto& p : memo) {
            if (memo2.find(p.first) == memo2.end()) continue;
            cnt += min(p.second, memo2[p.first]);
        }
        if (cnt < K) continue;
        int num = 1;
        for (auto& p : memo2) {
            num *= (p.second + 1);
        }
        if (max_num < num) {
            max_num = num;
            ans = i;
        }
    }
    cout << ans << endl;
    return 0;
}