Problems hooking up an original nintendo

my daughter is trying to hook up our old Nintendo(the very first nintendo) gaming system to our brand new Olevia TV. Well, we only have two cords. One cord connects to the back of the Nintendo and into the wall. The other cord connects into the back of the nintendo and has a small grey box near the end with a white cord that says (ant) and a black cord that says (tv). We hooked up the cord that says antenna to the back of the tv that says ANT. But, we do not what to do with the other cord that says TV. Please help in an way you can. We don't have the instruction manual either.