NOTE: (follows) I see people have shown you a Puck type adapter. (I actually have one of those and use it from time to time) this works well if you are plugging into an extension cord,, If you are connecting directly to a standard Wall Outlet (15 or 15/20 amp) Then a DOGBONE style (Where the plug and outlet have a short cord between them (With a right angle plug (the proper right angle) works better.
Now the NOTE: You said 50 amp to 110 volt, Should. be 50 amp to 15 amp, if you google search on 50 amp to 15 amp RV adapter you will be much happier.
This is important because it makes a difference when Googling (or otherwise searching the net) That is why I point it out.. Or you may also wish to reverse the numbers, Some makers put "RV to Outlet" some do "Outlet to RV"