program energii;
var f,g:text;
    v:array[0..6000]of longint;
    n,w,i,j,e,c:longint;
begin
assign(F,'energii.in');
assign(g,'energii.out');
reset(f);
rewrite(g);
read(f,n,w);
for i:=1 to w do v[i]:=-1;
for i:=1 to n do
  begin
    read(F,e,c);
    for j:=w downto e+1 do
      if (v[j-e]<>-1)then
        begin
          if (v[j]=-1)then v[j]:=v[j-e]+c else
            if (v[j-e]+c<v[j])then v[j]:=v[j-e]+c;
        end;
    for j:=e downto 1 do
      if (V[j]=-1)then v[j]:=c else
        if (c<v[j])then v[j]:=c;
  end;
write(g,v[w]);
close(F);
close(g);
end.