#include <fstream>

using namespace std;

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

int v[16001];

int main()
{
    int n, k;
    fin>>n>>k;

    int maxi = -1, s = 0;
    for(int i=0; i<n ; i++){
       fin>>v[i];

       if(maxi < v[i])
        maxi = v[i];

       s = s + v[i];
    }
    int max1 = -1;
    int st = maxi , dr = s, sol = -1, nr = 1;
    while(st <= dr && nr <= k){
        int so = 0;
        int m = (st + dr) / 2;
        for(int i = 1; i <= nr; i++)
            so = so + v[i];

        if(max1 <= so)
            max1 = so;

        sol = max1;
        nr++;

   }

    fout<<sol;
    return 0;
}