I would write it as:

perl -lne '$s += /^\w+\047?\w+\s+\w+\047?\w+\s/ }{ print $s' file.txt
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Update: After re-reading the original post again that should be:

perl -lne '$s += /^\w+(?:\047\w+)?\s+\w+(?:\047\w+)?/\s/ }{ print $s' 
+file.txt
[download]