program xmz;
var
f1,f2:text;
x:array[1..100000]of longint;
sum,a,n,m:longint;
function ok(nn:longint):boolean;
 var
 i,j,ss:longint;
 begin
  j:=1;ss:=0;
  for i:=1 to n do
    if ss+x[i]<=nn then inc(ss,x[i])
    else begin ss:=x[i];inc(j);end;
  if j<=m then ok:=true else ok:=false;
 end;
procedure cha(l,r:longint);
 var
 mid:longint;
 begin
  if l<>r then
  begin
  mid:=(l+r)div 2;
  if ok(mid) then cha(l,mid) else cha(mid+1,r);
  end
  else writeln(f2,l);
 end;
begin
 assign(f1,'expense.in');assign(f2,'expense.out');
 reset(f1);rewrite(f2);
 read(f1,n,m);
 for a:=1 to n do
  begin
   read(f1,x[a]);
   inc(sum,x[a]);
  end;
 cha(1,sum);
 close(f1);close(f2);
end.