Given a file that looks like this: 

[ -1, 5, 1 ],
[ 0, 5, 1 ],
[ 0, 5, 1 ],
[ 1, 5, 1 ],
[ 3, 4, 1 ],
[ 5, 1, 1 ],
[ 5, 0, 1 ],
[ 5, 0, 1 ],
[ 5, 0, 1 ],
[ 5, 0, 1 ],
[ 5, 0, 1 ],
[ 5, 0, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ 0, -5, 1 ],
[ -23, -64, 0 ],
[ -5, 0, 1 ],
[ -5, 1, 1 ],

[download]

I'm trying to collapse repeated lines that have a 0 in the 1st or the 2nd position into a single line that sums up the non-zero element while ignoring the 3rd one - i.e., 7 repeats of [ 0, -5, 1 ] should be replaced with [ 0, -35, 1 ]. All other lines should just be printed out. Unfortunately, my brain has decided to take a vacation today, and isn't being helpful - so I'm hoping for some Wisdom from the Monastery. :) 

-- 
I hate storms, but calms undermine my spirits.
 -- Bernard Moitessier, "The Long Way"

In reply to Summing up duplicate lines by oko1

Title:
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