#include <fstream>

using namespace std;
ifstream cin("transport.in");
ofstream cout("transport.out");
int n,k,maxx=0,s=0;
int v[16005];
int drumuri(int capacitate)
{
    int cnt=1,s=0;
    for(int i=0; i<n; i++)
    {
        if(s+v[i]<=capacitate)
            s+=v[i];
        else
            s=v[i],cnt++;
    }
    return cnt;
}
int cautbin(int st, int dr)
{
    int sol=-1;
    while(st<=dr)
    {
        int mid=(st+dr)/2;
        if(drumuri(mid)>k)
            st=mid+1;
        else
            sol=mid,dr=mid-1;
    }
    return sol;
}
int main()
{

    cin>>n>>k;
    for(int i=0; i<n;i++)
        cin>>v[i],s+=v[i],maxx=max(maxx,v[i]);
    cout<<cautbin(maxx,s);
    return 0;
}