rngs = [
    46644306:46644488,
    46644343:46644488,
    46648318:46648619,
    46648458:46648538,
    46648458:46648619,
    46648508:46648619,
    46648540:46648619,
    46649513:46649893,
    46649574:46649739,
    46649575:46649739,
    46649575:46649888,
    46649575:46649893,
    46651806:46652318,
    46652845:46652952,
    46653558:46654022,
    46656823:46658920,
    46658745:46658798,
    46658745:46658920,
    46658745:46659430,
    46658800:46659430,
    46660833:46660962,
    46660833:46661270,
    46660833:46661936,
    46661800:46661936,
    46663383:46663554,
    46664295:46664473,
    46664295:46664951,
    46664295:46665117,
    46664295:46665124,
]
function overlapsz(rng)
    bs = BitSet()
    for r in rng
        union!(bs, r)
    end
    return length(bs)
end