function Hailstones2(curr, count)
count=count+1
if curr==1: return count
if curr%2==0 : return Hailstones2(curr/2, count)
return Hailstones2((3*curr)+1, count)
end
function Hailstones(curr)
return Hailstones2(curr, 0)
end
print(Hailstones(13))
ZnVuY3Rpb24gSGFpbHN0b25lczIoY3VyciwgY291bnQpCgljb3VudD1jb3VudCsxCglpZiBjdXJyPT0xOiByZXR1cm4gY291bnQKCWlmIGN1cnIlMj09MCA6ICByZXR1cm4gSGFpbHN0b25lczIoY3Vyci8yLCBjb3VudCkKCXJldHVybiBIYWlsc3RvbmVzMigoMypjdXJyKSsxLCBjb3VudCkKZW5kCmZ1bmN0aW9uIEhhaWxzdG9uZXMoY3VycikKCXJldHVybiBIYWlsc3RvbmVzMihjdXJyLCAwKQplbmQKCnByaW50KEhhaWxzdG9uZXMoMTMpKQ==