#!/usr/bin/perl
use strict;
use warnings;

my @passwords = qw/ foo bar /;

my $count    = 0;
my $is_valid = 0;
while ( $count++ < 3  and  not $is_valid ) {
    print "Passwort eingeben: ";
    chomp( my $input = <STDIN> );

    $is_valid = grep { $input eq $_ } @passwords;
}

die "Access Denied\n" if not $is_valid;
print "Access Granted\n";