#include <vector>
#include <set>
#include <map>
#include <iostream>
using namespace std;
const int maxn = 33;
typedef long long ll;
ll a[maxn];
ll k;
int n;

bool check(ll x) {
    ll sum = 0;
    for(int i = 0; i < n; i++) {
        sum += x / a[i];
    }

    return sum >= k;
}
int main() {


    cin >> n >> k;
    for(int i = 0; i < n; i++) {
        cin >> a[i];
    }

    ll L = 0, R = 1e17;
    ll res = 1e18;
    while(L <= R) {
        ll mid = (L + R) / 2;
        if(check(mid)) {
            R = mid - 1;
            res = min(res, mid);
        }
        else {
            L = mid + 1;
        }
    }
    cout << res << endl;
    return 0;
}