Welcome to the forum.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
Will you be actually building this circuit?
If so, don’t.
Why? Because the LEDs require series resistors to limit current through them and the output pins of the UNO.
If you are only required to produce code then okay, but please point out to your instructor/teacher that if series resistors are not used then your UNO will not last long.
What we like to see is some code to show you have attempted to accomplish your goal.
Can you post some code that at least sets up your input buttons and outputs to LEDs.
Your idea of using a counter is the way to go, so some code where you increase and decrease a variable using the buttons would be good. If you have not been instructed that far, please let us know.