#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
	int a, b;
	cin >> a >> b;
	vector<ll> v(a);
	for (int i = 0; i < a; i++) {
		cin >> v[i];
	}
	priority_queue<ll, vector<ll>, greater<ll>> pq;
	for (int i = 0; i < b; i++) {
		pq.push(0);
	}
	for (int i = 0; i < a; i++) {
		ll x = pq.top();
		pq.pop();
		pq.push(x+v[i]);
	}
	for (int i = 1; i < b; i++) {
		pq.pop();
	}
	cout << pq.top() << endl;
}