use bigint;
$|=1;
$z=0;
$m=10**100;
while($m&&$r ne"="){
	$m/=2;
	print"? 1 $m\n";
	$r=<>;
	chop$r;
	if($r ne "<"){
		$z+=$m;
	}
}
print"! $z\n";