Mirko works in a sugar factory as a delivery boy. He has just received an order: he has to deliver **exactly ** kilograms of sugar to a candy store on the Adriatic coast. Mirko can use two types of packages, the ones that contain ** kilograms**, and the ones with ** kilograms** of sugar.

Mirko would like to take as few packages as possible. For example, if he has to deliver kilograms of sugar, he could use six -kilogram packages. But, it would be better to use three -kilogram packages, and one -kilogram package, resulting in the total of four packages.

Help Mirko by finding the minimum number of packages required to transport **exactly ** kilograms of sugar.

#### Input Specification

The first and only line of input contains one integer .

#### Output Specification

The first and only line of output should contain the minimum number of packages Mirko has to use. If it is impossible to deliver exactly kilograms, output `-1`

.

#### Sample Input 1

`4`

#### Sample Output 1

`-1`

#### Sample Input 2

`9`

#### Sample Output 2

`3`

#### Sample Input 3

`18`

#### Sample Output 3

`4`

## Comments

reminds me a lot about the CCCS2 from 2022