How to allow each user to do vote posts more than +1 or -1? ex: +3 or -2

Question

I need a feature to allow each user to vote an question or answer about -3 to +3

For a situation with low number of users, all users will vote, it could help us to highlighting the good question or answers.

I'm using this system as an idea management tool.

Comments

For example imagine this model instead of up and down arrows :

3 Green lights = +3 : Very very good idea
2 Green lights = +2 : Very good idea
1 Green lights = +1 : Good idea
No light = No vote = 0
1 Red lights = -1 : Bad idea
2 Red lights = -2 : Very bad idea
3 Red lights = -3 : Very very bad idea