If you have an error message, please tell Perl to RTFM for you. Add -Mdiagnostics to your command line.

$ perl -Mdiagnostics -e '%foo = 3'
... 
Odd number of elements in hash assignment at -e line 1 (#2)

    (S) You specified an odd number of elements to initialize a hash, 
+which
    is odd, because hashes come in key/value pairs.
$
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-- Randal L. Schwartz, Perl hacker