You need to start all your homework assignments with these lines in your file:

#!/usr/bin/perl
use warnings;
use strict;
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Start with something that you know will work in your file. Something like:

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

print "This is a test\n";
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Change one thing at a time and then run the script. Make sure you understand and correct any errors before adding anything else. Check your syntax frequently by running: "perldoc -f function"

If a piece of code compiles under warnings and strict but doesn't do what you want try adding print statments liberally in your code to check the values of your variables.