# For up to date code:
# https://github.com/codereport/bqn-code/blob/main/pwc/282-1.bqn

⟨Group⟩ ⇐ •Import "../lib/fun.bqn"

GoodInteger ← ⊑¯1∾˜·(3⊸=≠¨)⊸/Group

# Tests
•Show GoodInteger "12344456" # "444"
•Show GoodInteger "1233334"  # -1
•Show GoodInteger "10020003" # "000"