# include <fstream>
using namespace std;
ifstream fin ("transport.in");
ofstream fout ("transport.out");
int v[16005];
int n, k;
bool possible (int c)
{
    int currentk=0, currentv=0, i;
    for (i=0; i<n; i++)
    {
        if (currentv+v[i]<=c) currentv+=v[i];
        else
        {
            currentk++;
            currentv=v[i];
        }
    }
    currentk++;
    if (currentk<=k) return true;
    return false;
}
int main()
{
    int M=0, left, right, mid, i, sol=-1;
    fin>>n>>k;
    for (i=0; i<n; i++)
    {
         fin>>v[i];
         M=max(M, v[i]);
    }
    left=M;
    right=256005;
    while (left<=right)
    {
        mid=(left+right)/2;
        if (possible(mid))
        {
            sol=mid;
            right=mid-1;
        }
        else left=mid+1;
    }
    fout<<sol;
    return 0;
}