#include <iostream>
#include <fstream>

using namespace std;

int n, i, k, v[16001], mx, s, nr;
int st, dr, mid;

int main () {
    
    ifstream fin("transport.in");
    ofstream fout("transport.out");
    
    fin >> n >> k;
    mx = v[1];
    for (i = 1; i <= n; i++)
    {
        fin >> v[i];
        if (v[i] > mx)  mx = v[i];
        s += v[i];
    }
    
    bool ok = false;
    st = mx;    dr = s;
    while (st <= dr)
    {
        mid = st + (dr-st)/2;
        s = 0;  nr = 1;
        for (i = 1; i < n; i++)
        {
            s += v[i];
            if (s + v[i+1] >= mid)   {   nr++;   s = 0;   }
        }
        if (nr <= k)    ok = true;
        else ok = false;
        
        if (ok == true)     dr = mid-1;
        if (ok == false)    st = mid+1;
        //fout << st << " " << mid << " " << dr << "\n";
    }
    
    fout << mid << "\n";
}/*
  7
  3
  2
  3
  1
  4
*/