program ex;
const
 ss:array[1..3]of integer=(1,5,10);
 pp:array[1..3]of integer=(-1,2,5);
var
 f1,f2:text;
 s,p:longint;
 mint:longint;
procedure init;
 begin
  assign(f1,'goat.in');
  assign(f2,'goat.out');
  reset(f1);
  rewrite(f2);
  readln(f1,s,p);
  close(f1);
  mint:=maxint;
 end;
procedure pd(t:longint);
 begin
  if t<mint then mint:=t;
 end;
procedure try(t,ns,pt:longint);
 var
  i:integer;
 begin
  if t>=mint then exit;
  if ns>=s then pd(t)
           else begin
                 if pt>p then pt:=p;
                 for i:=3 downto 1 do
                  begin
                   if pt=0 then try(t+10,ns+10,pt+10);
                   if pt>pp[i] then try(t+1,ns+ss[i],pt-pp[i]);
                  end;
                end;

 end;
begin
 init;
 try(0,0,p);
 writeln(f2,mint);
 close(f2);
end.