#include <iostream>
#include<fstream>
int n,m,i,v[16001],d,x,s,k,t=0,nr,q,p,ok=0;
using namespace std;
ifstream f("transport.in");
ofstream g("transport.out");
int verif(int x,int k)
{
    int s=0;nr=n;q=k;
    while(nr>0)
    {
        s=s+v[nr];
        if(s>=x) {q--; s=0; nr++;}
        nr--;
    }
    if(s>0) q--;
    if(q==0) return 1;
    else if(q>0) return -1;
        else return 0;
}

int main()
{
    f>>n>>k;
    for(i=n;i>=1;i--)
    {
        f>>v[i];
        t=t+v[i];
    }
    s=v[n];
    d=t;
    while(s<=d)
    {
        m=(s+d)/2;
        if(verif(m,k)==1) {while(verif(m,k)==1) m--; g<<m; return 0;}
        else
        if(verif(m,k)==0) s=m+1;
        else if(verif(m,k)==-1) d=m-1;

    }
}