# by Artyom Bologov
H
# Remove all the non-bracket chars
g/.*/s/[^][]//gp
# Repeatedly remove all the simple matching brackets.
# Add more lines to handle deeper nested expressions.
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/\[\]/s///g
g/./s/.*/Not balanced!/
g/^$/s/.*/Balanced!/
,p
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