Two people are having a fun snowball fight. The fight begins with both people throwing a snowball at each other at the same time. After the -th person throws a snowball, it takes seconds before they throw another. Every snowball that is thrown will hit the other person. If the -th person is hit by at least snowballs, they will give up. If both people give up at the same time, the fight is a tie. Otherwise, the remaining person is declared the winner. What will be the outcome of the fight?

#### Constraints

#### Input Specification

The input consists of two lines. The first line contains two space-separated integers and . The second line contains two space-separated integers and .

#### Output Specification

Output a single integer: if the first person wins, if the second person wins, or if the fight is a tie.

#### Sample Input 1

```
2 3
2 4
```

#### Output for Sample Input 1

`1`

#### Explanation for Output for Sample Input 1

The first person is able to throw their second snowball after 3 seconds, forcing the second person to give up before they can throw their second snowball.

#### Sample Input 2

```
3 4
4 6
```

#### Output for Sample Input 2

`-1`

#### Explanation for Output for Sample Input 2

At seconds, the first person throws their **second snowball**.

At seconds, the second person throws their **second snowball**.
At seconds, the first person throws their third snowball.

At seconds, both players throw another snowball. The first person is hit by snowballs, and the second hit by , thus both give up at the same time.

## Comments