#include<fstream>
using namespace std;
ifstream f("transport.in");
ofstream g("transport.out");
int main()
{
    int n,k,v[20000],i,ok,s=0,maxx=0,tr,m;
    f>>n>>k;
    for(i=1;i<=n;++i)
    {
        f>>v[i];
        if(v[i]>maxx)maxx=v[i];
        s+=v[i];
    }
    maxx=(s+maxx)/2;
    tr=1;m=v[1];
    for(i=2;i<=n;++i)
        {
            if(v[i]+m>maxx){m=0;++tr;}
            m+=v[i];
        }
    if(tr>k)ok=0;
      else ok=1;
    while(ok==0)
    {
        ok=1;
        tr=1;m=v[1];
        for(i=2;i<=n;++i)
        {
            if(v[i]+m>maxx){m=0;++tr;}
            m+=v[i];
              if(tr>k){ok=0;++maxx;break;}
        }
    }
    while(ok==1)
    {
        ok=0;
        tr=1;m=v[1];
        for(i=2;i<=n;++i)
        {
            if(v[i]+m>maxx){m=0;++tr;}
            m+=v[i];
        }
        if(tr<=k)
        {
            --maxx;
            ok=1;
        }
    }
    g<<maxx+1;
    return 0;
}