Hi there, I'm trying to get out of sofia, and my plan was to go to Bratislava. I guess the night sleeper from Bucharest to Budapest is the most suitable for this, but I cannot seem to find a way to book a seat or bed online, without paying for the whole ticket. I am scared that if I book it in the train station, it will be sold out. I tried OBB, db and CFR. It is for tomorrow. Help is very appreciated, thank you in advance!