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