One of my favorite games I used to play on the SNES super Nintendo was Super Mario All Stars. It has a total of four games to choose from - Super Mario bros, Super Mario bros the lost levels, super Mario bros 2, and super Mario bros 3.
I get confused between super Mario bros 2 and super Mario bros the lost levels because in Japan I think they call the lost levels super Mario bros the lost levels #2. My question is which is the real super Mario bros 2? Lost levels or Mario bros 2? Also they used the same graphics on super Mario bros the lost levels as they did in super Mario bros.

This should help with your confusion: Super Mario Bros..

The real one is Super Mario Bros. 2 (in Japan: Super Mario USA).