#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;
typedef long long ll;
const int maxn = 33;

ll a[maxn];
int n;
ll K;

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

    if(res >= K){
        return true;
    }
    return false;
}
int main() {
    ios_base::sync_with_stdio(false);
    cin >> n >> K;

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


    ll L = 0, R = 1e18;

    ll res = 2e18;
    while(L <= R) {
        ll mid = (L + R) / 2;

        if(check(mid)) {
            res = min(res, mid);
            R = mid - 1;
        }
        else {
            L = mid + 1;
        }
    }
    cout << res << endl;
    return 0;
}