using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m) = (c[0], c[1]);
        var a = NList;
        var ok = 0;
        var ng = 1_000_000_001;
        while (ng - ok > 1)
        {
            var mid = (ok + ng) / 2;
            var t = 0L;
            var flg = true;
            for (var i = 0; i < n; ++i)
            {
                t += a[i] - mid;
                if (t < 0)
                {
                    flg = false;
                    break;
                }
            }
            if (flg) ok = mid;
            else ng = mid;
        }
        WriteLine(ok / m);
    }
}