Your question, (especially the "can't use the chop function" bit) smells a lot like homework. Please make an attempt at solving your problem, then show us what you've tried and we'll point out why it's failing.

As a further clue, take a look at perldoc perlre and the docs for the s/// operator in perldoc perlop.

'perldoc -q space'

Found in perlfaq4
  How do I strip blank space from the beginning/end of a string?
    Although the simplest approach would seem to be

        $string =~ s/^\s*(.*?)\s*$/$1/;

    not only is this unnecessarily slow and destructive, it also fails
+ with
    embedded newlines. It is much faster to do this operation in two s
+teps:

        $string =~ s/^\s+//;
        $string =~ s/\s+$//;

    Or more nicely written as:

        for ($string) {
            s/^\s+//;
            s/\s+$//;
        }

    This idiom takes advantage of the "foreach" loop's aliasing behavi
+or to
    factor out common code. You can do this on several strings at once
+, or
    arrays, or even the values of a hash if you use a slice:

        # trim whitespace in the scalar, the array,
        # and all the values in the hash
        foreach ($scalar, @array, @hash{keys %hash}) {
            s/^\s+//;
            s/\s+$//;
        }
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Do you wish to remove whitespace from the beginning and end of a sentence, line, or complete string? The implementation will be different for each of those scenarios. If from a sentence, your example text is not illustrating your problem, since " Martina is Princess " is not a complete sentence. It lacks punctuation, for one thing. Define what you mean by sentence.

chop is not selective enough about what it chops, nor is it designed to work on the beginning of a string.

During your "many times" of trying, what did you try?

I recommend reading perlfaq4, particularly the section called How do I strip blank space from the beginning and end of a string?.