program info;
type rucsac=record
       gr,c:integer;
    end;
var f,g:text;
    v:array[0..1002]of rucsac;
    castig:array[0..1002,0..5002]of longint;
   n,k,i,j:integer;
begin
   assign(f,'energii.in');  reset(f);
   assign(g,'energii.out');  rewrite(g);
   readln(f,n);
   readln(f,k);
   for i:=1 to n do
        readln(f,v[i].gr,v[i].c);

   for i:=1 to n do
     begin
        for j:=1 to k do
          begin
            if (v[i].gr<=j)and(castig[i-1,j-v[i].gr]+v[i].c>castig[i-1,j]) then
               castig[i,j]:=castig[i-1,j-v[i].gr]+v[i].c
             else
                castig[i,j]:=castig[i-1,j];
          end;
     end;
     writeln(g,castig[n,k]);
     close(f);
     close(g);
end.