Perica was always very good at math. His only weak points were addition and division. To help him with that, his teacher presented him with the following problem.

She gave him a by table, containing **positive** integers , , and .

We say that the **value** of a table is equal to:

Perica's task is to find the **minimum** number of degrees clockwise rotations required to maximize the value of a given table.

Result of a single clockwise rotation is shown below.

#### Input Specification

The first line of input contains two space separated integers, and .

The second line of input contains two space separated integers, and .

All integers are **positive** and not greater than .

#### Output Specification

The first and only line of output must contain a single integer, minimum number of clockwise rotations required to maximize the table's value.

#### Sample Input 1

```
1 2
3 4
```

#### Sample Output 1

`2`

#### Sample Input 2

```
5 9
7 2
```

#### Sample Output 2

`0`

#### Sample Input 3

```
41 99
100 13
```

#### Sample Output 3

`1`

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