What do you think about this?

It completely depends on your routine. There's no blanket answer to your question, but alarm bells always ring when people think about lumping legs in with shoulders. This usually indicates that they are not doing enough legs exercises. Legs are half your body - half your exercises should be training your legs.

if you can do a full leg workout and still have enough energy after to do a shoulder workout then you definatly did not work hard enough.  
legs are half your body, training legs in one day is like training chest, back, biceps, triceps, and shoulders in the same workout.  

I know. But it does INDICATE that something isn't right. If you are doing a 4DAW split, 1-2 of those workouts should be dedicated to legs. If you are splitting it up evenly then there would be no room for shoulders on a leg day (assuming you are only doing 1 leg day a week).

The short answer to your question is: I would put shoulders with chest.

However, I'm not convinced that you are ready to be doing a split routine in the first place. What are your lifts like? For example, can you squat 1.5x your bodyweight? If not then full body workouts will be more suitable for you.

i tried on leg day. shoulder on leg day is absolutely mess.. you just cant concentrate either one of em. and i feel like chest also takes out of you and you wouldnt have energy to concentrate on shoulders. i think best is to give shoulder its own day and maybe combine it with abs.

Man I can barely walk after legs day let alone do exercises like OHP after my workout. Just do it on chest day. Your shoulders are already used in all the big chest/tricep compound exercises, so it is a logical addition.