#include<fstream.h>
int main()
{int cs=0,max=0,v2[16001],i,in,n,k,c,v[16001];
ifstream q("transport.in");
ofstream w("transport.out");
q>>n>>k;
int s=0,nd=k+1;
for(i=1;i<=n;i++)
 {q>>v[i];
 if(max<v[i])
	max=v[i];
	s=s+v[i];}
i=0;
while(max<=s)
 {i++;
 v2[i]=max;
 cs++;
 max++;}
s=cs;
/*int nc,j,pos=0;
while(pos==0)
 {nc=s/2;
 nd=0;
 for(i=1;i<=n;i++)
	if(in+v[i]<=nc)
	 in=in+v[i];
	else
	 {nd++;
	 in=0;
	 i--;}
 if(nd<=k)
	s=s/2;
 else
	{for(i=1,j=s/2+1;i<=s/2,j<=s;i++,j++)
	 v2[i]=v2[j];
	s=s/2;}
	if(s==1)
	pos=0;}
w<<v2[1]; */
return 0;}