#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
int v[1000];
int main()
{
    int n,k,i=1,s=0,maxi;
    fin>>n>>k;///n=nr saltele;k=nr drumuri
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
        s=s+v[i];
    }
    i=1;
    int x=s/k;
    while(k>0)
    {
        int s2=0;
        if(s/k>x)
        {
            x=s/k;
        }
        if(s%k>0)
        {
            x++;
        }
        if(x>maxi)
        {
            maxi=x;
        }
        while(s2<x)
        {
            s2+=v[i];
            i++;
        }
        if(s2>x)
        {
            i--;
            s2=s2-v[i];
        }
         if(s2<x/2)
        {
            s2+=v[i];
            i++;
        }
        s=s-s2;
        k--;
    }
    fout << maxi << endl;
    return 0;
}