#include<iostream>
#include<cstring>
#include<algorithm>

#define ll long long
using namespace std;

const int N = 100010;

int n, k;
ll f[N];

ll check(int x)
{
    ll res = 0;
    for (int i = 1; i <= n; i++)
        res += f[i] / x;

    return res;
}

int main()
{
    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> f[i];

    sort(f + 1, f + 1 + n); 

    ll l = f[n] / k, r = f[n];

    if (!l)
    {
        cout << -1 << endl;
        return 0;
    }
    
    l = 1;
    while (l < r)
    {
        ll mid = (l + r + 1)/2;
        if (check(mid) >= k) 
           l = mid;
        else r = mid - 1;
    }

    cout << l << endl;

    return 0;
}