program expense;
type
fxz=array[1..100000] of longint;
var
f1,f2:text;
n,m,max,ans,i,x:longint;
a:fxz;


      procedure chu(l,r:longint);
      var
      flag:boolean;
            procedure pan(xx:longint);
            var
            i,p:longint;
            ls:fxz;
            begin flag:=false;p:=1;
                  for i:=1 to n do ls[i]:=0;
                  for i:=1 to n do begin
                                         while (ls[p]+a[i]>xx)and(p<=m) do inc(p);
                                               if p<=m then ls[p]:=ls[p]+a[i]
                                                        else break;
                                    end;
                  if p<=m then flag:=true;
            end;



      begin if l=r then ans:=l
                   else begin x:=(l+r) div 2;
                              flag:=false;
                              pan(x);
                              if flag then chu(l,x)
                                      else chu(x+1,r);
                         end;
      end;






begin assign(f1,'expense.in');
      assign(f2,'expense.out');
      reset(f1);rewrite(f2);
      readln(f1,n,m);
      max:=0;
      for i:=1 to n do
      begin readln(f1,a[i]);
            max:=a[i]+max;
      end;

      chu(1,max);

      writeln(f2,ans);
      close(f1);close(f2);
end.