#include<stdio.h>
int x[16005],N,K,s;
int trans (int c)
	{
   int i,nt=0,V=0;
	for (i=1;i<=N;i++)
      if (x[i]>c) return K+1;
      else
      	{
   		if (V+x[i]<=c) V+=x[i];
			else
   			{
      		V=x[i];
      		nt++;
      		}
         }
   if (V<c) nt++;
   return nt;
   }

int bsd()
	{
   int st,dr,med,last=-1;
	st=1;
	dr=s;
	while (st<=dr)
		{
		med=st+(dr-st)/2;
		if (trans(med)<=K)
			{
			dr=med-1;
			last=med;
			}
		else st=med+1;
		}
	return last;
	}

int main()
{
freopen("transport.in","r",stdin);
freopen("transport.out","w",stdout);
int i;
scanf("%d%d",&N,&K);
for (i=1;i<=N;i++)
	{
	scanf("%d",&x[i]);
   s+=x[i];
   }
printf("%d",bsd());
return 0;
}