function Hailstones(curr)
	return Hailstones(curr, 0)
function Hailstones(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

print(Hailstones(13))