Filling one column with a set value depending on the adjacent cell

I have two columns L and M. If I enter "full" into a cell in column L, I would like "65" to automatically be entered into adjacent cell in column M. If the cell in column L does not say full, I would like "45" to be entered into the cell in column M.

I have been trying to use an IF function to do so, but I cannot get it to work. Am I using the wrong function?