#include <iostream>
#include <fstream>

using namespace std;

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

int d,v[16003],maxi,sum,n;

int numara_drumuri(int capca)
{
    int nrd=0,s=0;
    for (int i=0; i<n;)
    {
        ///pregatim un drum
        while (s+v[i]<=capca)
        {
            s+=v[i]; /// punem o saltea
            i++; /// trecem la urmatoarea saltea
        }
        nrd++;
        s=0;
    }
    return nrd;
}

int caut_bin(int maxi, int suma)
{
    int  st=maxi,dr=suma,mj=(st+dr)/2,bestcamion=-1;
    while (st<=dr)
    {
        mj=(st+dr)/2;
        if (numara_drumuri(mj) <= d)
        {
            ///am gasit un camion
            bestcamion=mj;
            dr = mj-1;
        }
        else
        {
            /// inseamna ca camionula face prea multe drumuri
            ///incercam un camion mai mare
            st = mj+1;
        }
    }
    return bestcamion;
}

int main()
{
    int solutie;
    fin>>n>>d;
    for (int i=0; i<n; i++)
    {
        fin>>v[i];
        if (v[i] > maxi)
        {
            maxi=v[i];
        }
        sum+=v[i];
    }
    solutie=caut_bin(maxi,sum);
    fout<<solutie;
    return 0;
}