program pascal;
var f,h:text; i,j,n,g,min:longint;
    y,c,gr:array[0..20000] of longint;
 procedure citire;
 begin
 assign(f,'energii.in'); reset(f);
 assign(h,'energii.out'); rewrite(h);
 readln(f,n); readln(f,g);
 for i:=1 to n do
        readln(f,c[i],gr[i]);
 close(f);
 end;

 procedure dinamik;
 begin
 y[0]:=0;
 for i:=1 to 20000 do y[i]:=maxlongint;
 for i:=1 to n do
 for j:=g downto 0 do
  if y[j]<>maxlongint then
           if y[j]+gr[i]<y[j+c[i]] then y[j+c[i]]:=y[j]+gr[i];
  min:=maxlongint;
  for i:=g to 20000 do
  if y[i]<min then min:=y[i];
  if min=maxlongint then min:=-1;
 end;

 procedure afisare;
 begin
 write(h,min);
 close(h);
 end;

begin
citire;
dinamik;
afisare;
end.