Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately.
农夫约翰已经获悉逃跑的牛的位置，想立刻抓住它。
He starts at a point N (0 ≤ N ≤ 100,000) on a number line and the cow is at a point K (0 ≤ K ≤ 100,000) on the same number line. Farmer John has two modes of transportation: walking and teleporting.
农夫的位置在直线上的N (0 ≤ N ≤ 100,000)点，牛在同一直线上的 K (0 ≤ K ≤ 100,000)点，约翰有步行和闪移两种走法。
* Walking: FJ can move from any point X to the points X - 1 or X + 1 in a single minute
步行：农夫约翰可以一分钟从点X走到X-1或X+1点
* Teleporting: FJ can move from any point X to the point 2 × X in a single minute.
闪移：农夫约翰可以一分钟从点X走到2*X点
If the cow, unaware of its pursuit, does not move at all, how long does it take for Farmer John to retrieve it?
假设奶牛并没有意识被追，还在站在原地，农夫约翰需要多少步，才能把奶牛逮住？
Input
Output
Sample Input
5 17
Sample Output
4
Hint
The fastest way for Farmer John to reach the fugitive cow is to move along the following path: 5-10-9-18-17, which takes 4 minutes.
提示：
注意下标防止出界，注意可以回走