You need a 3/32" wide chain. Wmart has a chain by bell called speedy which will work. Pick up a chain breaker at Wmart so that you can break the chain to make it the correct length.

To determine the chain length run the chain around the large front ring and the large rear cog without going through the rear derailuer or the front derailuer if possible. Pull the chain tight and then break the chain so that it is at least two links longer. Sometimes you will have to go 3 links so that the chain will mate back together using the quick connect. This one inch increase in length will allow the chain to shift into the large front and large back cog without damaging anything.

Now route the chain through the derailuers and snap it together and go ride.