#include <iostream>
#include <fstream>
using namespace std;
ifstream in("transport.in");
ofstream out("transport.out");
int main()
{
    int n,k,v[16001],i,s=0,ok=0,k2,s2;
    in>>n>>k;
    for(i=1;i<=n;i++)
    {
        in>>v[i];
        s+=v[i];
    }
    s/=2;
    while(ok!=1)
    {
        k2=0;
        s2=0;
        for(i=1;i<=n;i++)
        {
            s2+=v[i];
            if(s2>s)
            {
                s2=v[i];
                k2++;
            }
        }
        k2++;
        if(k2>k)
        ok=1;
        else if(k2<k || k2==k)
        s--;
    }
    out<<s+1;
    return 0;
}