program energii;
var i,j,n,g:integer;  f,t:text;
    castig,alege:array[0..1001]of integer;
    gr,c:array[1..1001]of integer;
begin
   assign(f,'energii.in');reset(f);
   assign(t,'energii.out');rewrite(t);
    readln(f,n);readln(f,g);
      for i:=1 to n do readln(f,gr[i],c[i]);
    for i:=1 to n do
      for j:=1 to g do
      if gr[i]<=j then
       if c[i]+castig[j-gr[i]]>castig[j] then
       castig[j]:=c[i]+castig[j-gr[i]];
       write(t,castig[g]);
       close(f);close(t);
      end.