use strict;
use warnings;

my $num;

do {
	chomp( $num = <> );
} until $num eq '47';

print $num;

##</code><code>##

use strict;
use warnings;
use Term::ReadKey;

my $num;
ReadMode 'noecho';

do {
	chomp( $num = ReadLine(0) );
} until $num eq '47';

ReadMode 'restore';
print $num;