#include <iostream>
#include <fstream>
#define nmax 16000

using namespace std;
ifstream f("transport.in");
ofstream g("transport.out");

int v[nmax], maxCamion, sumaMomentana, kMomentan, ok = 0;

int main()
{
    int n, k;
    f >> n >> k;
    for (int i = 1; i <= n; i++) {
        f >> v[i];
        if (maxCamion < v[i]) maxCamion = v[i];
    }
    while (1) {
        for (int i = 1; i <= n; i++) {
            sumaMomentana += v[i];
            ok = 0;
            if (sumaMomentana > maxCamion) {
                kMomentan++;
                sumaMomentana = v[i];
                if (sumaMomentana < maxCamion) ok = 1;
            }
            else ok = 0;
        }
        if (ok == 1) kMomentan++;
        if (kMomentan <= k) {
            g << maxCamion ;
            return 0;
        }
        else {
            maxCamion++;
            kMomentan = 0;
        }
    }
    return 0;
}