#include <fstream>
#include <iostream>

using namespace std;

ifstream fin("transport.in");
// ofstream cout("transport.out");
int v[16005], n, k, maxim;

int f(int capacitate) { // returneaza cate transporturi face
    int incarcatura = 0, transporturi = 1;
    for(int i = 1; i <= n; i ++) {
        incarcatura += v[i];
        if(incarcatura > capacitate) {
            transporturi ++;
            incarcatura = v[i];
        }
    }
    return transporturi;
}

int main() {
    fin >> n >> k;
    for(int i = 1; i <= n; i ++) {
        fin >> v[i];
        if(v[i] > maxim)
            maxim = v[i];
    }
    int st = maxim, dr = 256000000, mij, cautare = -1;
    while(st <= dr) {
        mij = (st + dr) / 2;
        if(f(mij) <= k) {
            dr = mij - 1;
            cautare = mij;
        }
        else
            st = mij + 1;
    }
    cout << cautare << '\n';
    return 0;
}