#include <fstream>
#define NMAX 16000
using namespace std;

int n,v[NMAX+1],k;
int maxim=0,suma=0;

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

int calcNum(int val)
{
    int nri=1,sum=0;
    for(int i=1; i<=n; i++)
    {
        sum+=v[i];
        if(sum>val)
        {
            sum=v[i];
            nri++;
        }
    }
    return nri;
}

int main()
{
    fin>>n>>k;
    for(int i=1; i<=n; i++)
    {
        fin>>v[i];
        suma+=v[i];
        if(v[i]>maxim)
        {
            maxim=v[i];
        }
    }

    int st=maxim,dr=suma;
    int sol=-1;
    while(st<=dr)
    {
        int mij=(st+dr)/2;
        int interv=calcNum(mij);

        if(interv<=k)
        {
            //caut in stanga
            sol=mij;
            dr=mij-1;
        }
        else if(interv>k)
        {
            st=mij+1;
        }
    }
    fout<<sol;
    return 0;
}