program expense(input,output);
var
 a:array[1..100000]of longint;
 i,j,k,n,m,ans,sum,min,max,mid:longint;
begin
 assign(input,'expense.in');assign(output,'expense.out');
 reset(input);rewrite(output);
 readln(n,m);
 sum:=0; min:=0;
 for i:=1 to n do begin
  readln(a[i]);
  sum:=sum+a[i];
  if a[i]>min then min:=a[i];
 end;
 max:=sum;
 while min<max do begin
  k:=0;
  sum:=0;
  mid:=(min+max)div 2;
  for i:=1 to n do begin
   sum:=sum+a[i];
   if sum>mid then begin inc(k); sum:=a[i]; end;
  end;
  if k<m then max:=mid else min:=mid+1;
 end;
 writeln(max);
 close(input);close(output);
end.