Looks like you are running afoul of the "special" argument handling that is done by the "print" function,

That's completely wrong. It has nothing to do with print, and all to do with the meaninglessness of the space before opening paren.

$ perl -le'sub f { print("@_"); } f (5) + 4'
5
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Or with warnings:

$ perl -wle'sub f { print("@_"); } f (5) + 4'
Useless use of addition (+) in void context at -e line 1.
5
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In the code in question,

print (v('I')+1)*26 + v('V'), "\n";
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means

print( v('I')+1 )
   * 26
      + v('V'),
"\n";
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