## 3012: 抓住那头奶牛 ( catch ) usaco 2007 Open silver

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## 题目描述

Farmer John has been informed of the location of a fugitive cow and wants to catch her immediately.

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.

* Walking: FJ can move from any point X to the points - 1 or + 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?

Input

Line 1: Two space-separated integers: N and K

Output

Line 1: The least amount of time, in minutes, it takes for Farmer John to catch the fugitive cow.

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.

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