#include <fstream>
#include <vector>
using namespace std;

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

vector <int> v;

int rez, n, k, s, d,c;

int b_search(int st, int dr, int val)
{
	int rez = 0;
	while (st <= dr)
	{
		int mij = (st + dr) / 2;
		if (v[mij] - v[c] <= val)
		{
			rez = mij;
			st = mij + 1;
		}
		else dr = mij - 1;
	}
	return rez;
}

bool check(int x)
{
	int ant = 1;
	c = 0;
	for (int i = 1; i <= k; ++i)
	{
		ant = b_search(ant, n, x);
		c = ant;
		if (ant == 0)
			return 0;
		if (ant == n)
			return 1;
		++ant;
	}
	return 0;
}

int main()
{
	fin >> n >> k;
	v.resize(n + 1);

	for (int i = 1; i <= n; ++i)
	{
		fin >> v[i];
		if (v[i] > s) s = v[i];
		v[i] += v[i - 1];
	}

	d = v[n];
	rez = v[n];
	while (s <= d)
	{
		int mij = (s + d) / 2;
		if (check(mij))
		{
			if (mij < rez) rez = mij;
			d = mij - 1;
		}
		else s = mij + 1;
	}

	fout << rez << "\n";

	return 0;
}