#include <fstream>

using namespace std;

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

int n, k, sol;

int st[16002], a[16002], top;

int main()
{
    int i, val, cntk = 1, sum = 0;
    fin >> n >> k;
    for(i = 1; i <= n; i++)
        fin >> a[i];
    val = a[1];
    for(i = 1; i <= n; i++)
    {
        if(sum + a[i] <= val)
            sum += a[i];
        else if(cntk == k && sum + a[i] > val)
        {
            val = a[i] + sum;
            sum += a[i];
        }
        else if(sum + a[i] > val)
        {
            sum = a[i];
            cntk++;
        }
    }
    fout << val;
    return 0;
}