#include <iostream>
#include <fstream>

using namespace std;
ifstream f("transport.in");
ofstream g("transport.out");
int n,k,k2,i,j,vol,volf,v[16001],pas=134217728,ok,sum;

int main()
{
    f>>n>>k;
    for(i=1;i<=n;i++)
    {
        f>>v[i];
    }
    vol=0; volf=0;
    while(pas)
    {
        vol=volf+pas;
        ok=0;
        k2=1; sum=0;
        for(i=1;i<=n;i++)
        {
            if(sum+v[i]<=vol) sum+=v[i];
            else sum=v[i], k2++;
        }
        if(k2>k) ok=0;
        else ok=1;
        if(!ok) volf=vol;
        pas/=2;
    }
    g<<volf-1<<'\n';
    return 0;
}