const maxn=16000;oo=maxlongint div 4;
var t:Text;
   V,S:Array[0..maxn]of longint;
   i,n,k,lo,hi,juma,sol:longint;
   function work(cap:longint):boolean;
   var i,lo:longint;
   begin
      lo:=0;V[0]:=0;
      for i:=1 to N do
      begin
         while (lo<i-1)and(S[i]-S[lo]>cap)do inc(lo);
         V[i]:=1+v[lo];
      end;
      work:=V[n]<=K;
   end;
begin
   assign(t,'transport.in');reset(T);readln(t,n,k);
   for i:=1 to N do begin readln(T,S[i]);if s[i]>lo then lo:=s[i];inc(S[i],S[i-1]);end;
   close(t);sol:=oo;hi:=S[n];
   while lo<=hi do
   begin
      juma:=(lo+hi)div 2;
      if not work(juma) then lo:=juma+1 else
      begin hi:=juma-1;if juma<sol then sol:=juma;end;
   end;
   assign(T,'transport.out');rewrite(T);writeln(t,sol);close(T);
end.