#include <fstream>
#include <algorithm>

using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
const int NMAX=16005;
int v[NMAX],n,k;

bool ok(int med)
{
    int s=0,i,cnt=0;
    for(i=1;i<=n;i++)
    {
        s+=v[i];
        if(s>med)
        {
            s=v[i];
            cnt++;
        }
    }
    if(s!=0)
        cnt++;
    if(cnt<=k)
        return 1;
    return 0;
}

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