:import std/Combinator .
:import std/String .
:import std/Number .
:import std/Char C
:import std/Pair P
self [[(zip 0) ∘ (drop 1) ∘ cycle 0]]
main [φ (cons ⋔ solve) part1 part2 (C.char→number <$> (trim 0))]
solve (filter (P.uncurry eq?)) → (foldl \(g add head) (+0))
part1 self (+1)
part2 self /²(length 0)