Is it possible to exclude values when creating SUM in google sheets?

I have a profit sheet I use, and in my profits column I would like to create a SUM of the whole column whilst excluding the numbers which are negative. Anyone have any ideas of how to do this? It's a long column and manually excluding the numbers one by one would take time. The negative numbers are marked by - if that helps.

I'd imagine it needs an IF statement but i'm not too sure.

Any help would be appreciated, thanks!