#include <iostream>
#include <fstream>

using namespace std;

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

int n,k,v[16001];

bool ok(int c)
{
    int tr,s,i;
    s=0;
    tr=0;
    for(i=1;i<=n;i++)
    {
        if (v[i]>c)
            return 0;
        if(s+v[i]<=c)
        {
            s=s+v[i];
        }
        else
        {
            tr++;
            s=v[i];
        }
    }
    if(s>0)
        tr++;
    return tr<=k;
}
int bs(int st,int dr)
{
    int med, last = -1;
    while(st<=dr)
    {
        med=(st+dr)/2;
        if(ok(med))
        {
            last=med;
            dr=med-1;
        }
        else
            st=med+1;
    }
    return last;
}

int main()
{
    int s=0;
    fin>>n>>k;
    for (int i=1;i<=n;i++)
    {
        fin>>v[i];
        s=s+v[i];
    }
    fout<<bs(1,s);
    return 0;
}