program Excl1;
var
n, m, r: Integer;
s, t: LongInt;
begin
Write('n>');
Readln(n);
Write('m>');
Readln(m);
t := n;
s := 1;
while t <= m do
begin
r := t;
Inc(t, s * s);
s := s shl 1;
end;
Writeln( r );
end.