//KZNS
#include <cstdio>
#include <queue>
#include <vector>
using namespace std;
class cp {
    public:
        bool operator () (const int a, const int b) {
            return a > b;
        }
};
int main() {
    freopen("waterj.in", "r", stdin);
    freopen("waterj.out", "w", stdout);
    int N, M;
    scanf("%d %d", &N, &M);
    priority_queue<int, vector<int>, cp> ls;
    for (int i = 0; i < M; i++)
        ls.push(0);
    int u, a;
    for (int i = 0; i < N; i++) {
        scanf("%d", &a);
        u = ls.top();
        ls.pop();
        ls.push(u + a);
    }
    for (int i = 0; i < M; i++) {
        u = ls.top();
        ls.pop();
    }
    printf("%d\n", u);
    return 0;
}
//UBWH