Hello, I want to see as much as I can for the 1 day available. My ideal plan would be to train travel from Lucern to Lauterbrennen. Lauterbrunnen to Grindlewald. Grindlewald to Interlaken and then a boat to Brienz and finally catching the train back to Lucern. Is this possible or will I be on a train all day? Thank you for any advice.