#include <fstream>
using namespace std;
const int NMAX=16000;
int v[NMAX+5];//16.005*4b=64mb
int n,k;
ifstream fin("transport.in");
ofstream fout("transport.out");
bool ok(int c)
{
	int i,sc,tr;
	sc=0;
	tr=0;
	for(i=1;i<=n;i++)
	{
		if(v[i]>c)
			return 0;
		if(sc+v[i]<=c)
			sc=sc+v[i];

	else
		{
			tr++;
			sc=v[i];
		}
	}
	tr++;
	return tr<=k;
}
int bsl(int st,int dr)
{
	int med,last=-1;
	while(st<=dr)
	{
		med=(st+dr)/2;
		if(ok(med))
		{
			last=med;
			dr=med-1;
		}
		else
			st=med+1;
	}
	return last;
}
int main()
{
    int i,s;
    fin>>n>>k;
    s=0;
    for(i=1;i<=n;i++)
    {
    	fin>>v[i];
    	s=s+v[i];
    }
    fout<<bsl(1,s);
    fin.close();
    fout.close();
    return 0;
}