#include <iostream>
#include <algorithm>
#include <vector>
#include <fstream>

using namespace std;
long long int n,i,x,k,c,s,st,dr,med,poz,maxi;
vector<long long int>v;

int main()
{
    ifstream fin("transport.in");
    ofstream fout("transport.out");
    fin>>n>>k;
    for (i=0;i<n;i++)
    {
        fin>>x;
        v.push_back(x);
        s=s+x;
        if (maxi<x) maxi=x;
    }
    st=maxi;
    dr=s;
    while (st<=dr)
    {
        med=(st+dr)/2;
        x=0;
        c=1;
        for (i=0;i<v.size();i++)
        {
            x=x+v[i];
            if (x>med)
            {
                x=v[i];
                c++;
            }
        }
        if (c>k)
        {
            st=med+1;
        }
        if (c<=k)
        {
            poz=med;
            dr=med-1;
        }
    }
    fout<<poz;
}