#include <fstream>
using namespace std;

ifstream cin("transport.in");
ofstream cout("transport.out");

int v[16001];

int main()
{

    int n,k,i,maxi=-1,s=0,st,dr,mijl,t,sol=-1;
    cin>>n>>k;
    for(i=1;i<=n;i++){
		cin>>v[i];
		if(v[i]>maxi)
			maxi=v[i];
		s+=v[i];
    }
    st=maxi;
    dr=s;
    while(st<=dr){
		mijl=(st+dr)/2;
		s=0;
		t=1;
		for(i=1;i<=n;i++)
			if(s+v[i]<=mijl)
				s+=v[i];
			else{
				s=v[i];
				t++;
			}
		if(t>k)
			st=mijl+1;
		else{
			sol=mijl;
			dr=mijl-1;
		}
    }
    cout<<sol;

    return 0;
}