## Provably fair giveaway manager

As the `blockhash`

is just a number, its last 6 digits is converted to `decimal`

using
this function:

`var decimal = parseInt(blockhash.slice(-6), 16);`

Now we have an integer (0 to 16777215) from the `blockhash`

.

After dividing this `decimal`

by the number of participants, we use the *modulo operator
( %)*
to get the division remainder becomes
the

`index_number`

.This `index_number`

is applied in the participants list, to get the position of the winner.

```
var index_number = decimal % competitors.length;
```

```
var winner = competitors[index_number];
```

For additional winners, the past winners are removed from the list and one more digit is added from the blockhash. A maximum 30 was added to avoid working with big numbers.