question on declaring variables

[badbanana]

i have this two files below. the first one produces no errors but the second one produces the following errors:

Global symbol "$x" requires explicit package name (did you forget to declare "my $x"?) at ./two.pl line 6.
Global symbol "$y" requires explicit package name (did you forget to declare "my $y"?) at ./two.pl line 7.
Global symbol "$x" requires explicit package name (did you forget to declare "my $x"?) at ./two.pl line 10.
Global symbol "$y" requires explicit package name (did you forget to declare "my $y"?) at ./two.pl line 13.
Global symbol "$x" requires explicit package name (did you forget to declare "my $x"?) at ./two.pl line 15.
Global symbol "$y" requires explicit package name (did you forget to declare "my $y"?) at ./two.pl line 15.
Execution of ./two.pl aborted due to compilation errors.

this is file 1:

#!/usr/bin/perl

use warnings;
use strict;

$a=0;

chomp($a=<STDIN>);
print $a, "\n";

and this is file 2:

#!/usr/bin/perl

use warnings;
use strict;

$x=0;
$y=0;

print "enter first number ";
chomp($x=<STDIN>);

print "enter second number ";
chomp($y=<STDIN>);

print "Product ",$x*$y, "\n";

i can't seem to figure out what's causing the errors for file 2. the declaration is the same in both files.

[toolic]

Yes, the declaration is the same for both files, but $a is a special variable, whereas $x and $y are not. You get the error messages because you correctly use strict:

Because of their special use by sort(), the variables $a and $b are exempted from this check.

You should avoid using $a and $b because they are special for the sort function. As the helpful message reports, you need to declare x and y with my.

[badbanana]

oh i see. thanks, got it!