#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("transport.in");
ofstream fout("transport.out");

int n, k;
const int NMAX = 16000;
int v[NMAX + 5];

int ok(int C)
{
    int i, s, tr;
    s = 0;
    tr = 0;

    for(i = 1; i <= n; ++i)
    {
        if(v[i] > C)
        {
            tr = k + 1;
            break;
        }
        if(s + v[i] <= C)
            s += v[i];
        else
        {
            tr++;
            s = v[i];
        }



    }
    if(s > 0)
        tr++;

    return tr;
}

int bs(int st, int dr)
{
    int med, last = -1;

    while(st <= dr)
    {
        med = (st + dr) / 2;

        if(ok(med) <= k)
        {
            last = med;
            dr = med - 1;
        }
        else
            st = med + 1;
    }
    return last;
}

int main()
{
    int i, S = 0;

    fin >> n >> k;

    for(i = 1; i <= n; i++)
    {
        fin >> v[i];

        S += v[i];
    }

    fout << bs(1, S);




    fin.close();
    fout.close();
    return 0;
}