﻿ AGC014 A - Cookie Exchanges - Atcoder

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Score : $300$ points

### Problem Statement

Takahashi, Aoki and Snuke love cookies. They have $A$, $B$ and $C$ cookies, respectively. Now, they will exchange those cookies by repeating the action below:

• Each person simultaneously divides his cookies in half and gives one half to each of the other two persons.

This action will be repeated until there is a person with odd number of cookies in hand.

How many times will they repeat this action? Note that the answer may not be finite.

### Constraints

• $1 ≤ A,B,C ≤ 10^9$

### Input

Input is given from Standard Input in the following format:

$A$ $B$ $C$


### Output

Print the number of times the action will be performed by the three people, if this number is finite. If it is infinite, print -1 instead.

### Sample Input 1

4 12 20


### Sample Output 1

3


Initially, Takahashi, Aoki and Snuke have $4$, $12$ and $20$ cookies. Then,

• After the first action, they have $16$, $12$ and $8$.
• After the second action, they have $10$, $12$ and $14$.
• After the third action, they have $13$, $12$ and $11$.

Now, Takahashi and Snuke have odd number of cookies, and therefore the answer is $3$.

### Sample Input 2

14 14 14


### Sample Output 2

-1


### Sample Input 3

454 414 444


### Sample Output 3

1