Counting the number of added values in a cell

Hey guys, first time posting here. I have an excel sheet where i add numbers, for example in a cell i will type =12+12+15
after i push enter, the cell will read 39.
Later i want to have another cell output the number 3, which counted the number of numbers i previously added. Is this possible? Every function i find works on the 39, but how do i get a cell to output the number 3 in this example.

Thanks for your help, i really appreciate it.