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#F0476. Power Hungry Cows

    ID: 482 传统题 1000ms 64MiB 尝试: 0 已通过: 0 难度: (无) 上传者: 标签>待分类整理状态难度待定难度共享题库高校与竞赛共享题英文题面题目来源题面语言

Power Hungry Cows

题目描述

FJ's cows would like to be able to compute integer powers P (1 <= P <= 20,000) of numbers very quickly, but need your help. Because they're going to be computing powers of very large numbers, they can only keep around two work variables for intermediate results.

The first of those work variables is initialized to the number (denoted x) for which they are calculating the power; the other is initialized to 1. The cows can both multiply and divide any pair of the work variables and store the result in any work variable, but all results are stored as integers.

For example, if they want to compute x^31, one way to perform the calculation is:
                                              WV1  WV2

Start: x 1
Multiply first by first, store in second: x x^2
Multiply second by second: x x^4
Multiply second by second: x x^8
Multiply second by second: x x^16
Multiply second by second: x x^32
Divide second by first: x x^31

Thus, x^31 can computed in six operations. Given the power to be computed and the the number of work variables, find the minimum number of operations to calculate the power.

输入格式

A single line with one integer: P.

输出格式

A single line with a single integer that is the minimum number of operations it requires to compute the power.

样例 1

输入

31

输出

6

题目来源:USACO 2002 February;FPS 共享题包,题包内第 2 题。保留原作者与原赛事署名。