function Hailstones2(curr, count)
if curr==1: return count+1
count=count+1
if curr%2==0 : return Hailstones(curr/2, count)
return Hailstones((3*curr)+1, count)
end
function Hailstones(curr)
return Hailstones2(curr, 0)
end
print(Hailstones(13))
ZnVuY3Rpb24gSGFpbHN0b25lczIoY3VyciwgY291bnQpCglpZiBjdXJyPT0xOiByZXR1cm4gY291bnQrMQoJY291bnQ9Y291bnQrMQoJaWYgY3VyciUyPT0wIDogIHJldHVybiBIYWlsc3RvbmVzKGN1cnIvMiwgY291bnQpCglyZXR1cm4gSGFpbHN0b25lcygoMypjdXJyKSsxLCBjb3VudCkKZW5kCmZ1bmN0aW9uIEhhaWxzdG9uZXMoY3VycikKCXJldHVybiBIYWlsc3RvbmVzMihjdXJyLCAwKQplbmQKCnByaW50KEhhaWxzdG9uZXMoMTMpKQ==