It totally depends on the type of complexity you are trying to find. let me explain this case wise.
In case if you are trying to find out the time complexity then you have to add the constant as even reading a single word would take some time.
If you are trying to find out the number of addition, multiplication or comparision in this case do check whether the respection operation is being performed in the also or not. if yes them add the number of times that operation is performed but generally we add constant.
In case of value you need to be bit careful with the constant, for that i would suggest you to practice some examples.
Hope this helps.