#include <iostream>
#include <fstream>

using namespace std;

int v[16061];

int main()
{
    ifstream fin ("transport.in");
    ofstream fout ("transport.out");
    int n,k,s=0,a;
    fin>>n>>k;
    for (int i=1;i<=n;++i)
    {
        fin>>v[i];
        s+=v[i];
    }
    a=(s+k-1)/k;
    int volum=0,nr=0;
    for (int i=1;i<=n;++i)
    {
        nr+=v[i];
        if (nr>=a)
        {
            if (volum<nr)
            {
                volum=nr;
            }
            nr=0;
        }
    }
    fout<<volum;
}