#include <iostream>
#include <fstream>
using namespace std;
ifstream in("transport.in");
ofstream out("transport.out");
int main()
{
    int n, k, sol;
    in >> n >> k;
    int v[n], maxim = -1, s = 0;
    for(int i = 1; i <= n; i ++)
    {
        in >> v[i];
        s += v[i];
        if(v[i] > maxim)
        {
            maxim = v[i];
        }
    }
    int st = maxim;
    int dr = s;
    while(st <= dr)
    {
        int mijl = (st + dr )/ 2;
        int aux = mijl;
        int nr = 0;
        for(int i = 1; i <= n - 1; i ++)
        {
            if(v[i] <= aux)
            {
                aux -= v[i];
                if(aux < v[i +1])
                {
                    aux = mijl;
                    nr ++;
                }
            }
        }
        if(nr + 1 > k)
        {
            st = mijl + 1;
        }
        else
        {
            dr = mijl - 1;
            sol = mijl;
        }
    }
    out << sol;
}